Easter Eggs

Easter Eggs are fun surprises in Yandere Simulator that the player must discover in order to use.

YandereDev has included many Easter Eggs in the debug builds of the game. These are usually added when YandereDev does not have enough time to write code for the game. They include wearable accessories for Yandere-chan, game modes, a small timed event at the starting menu, references to several anime characters or in-game jokes, and a phantom. The final game may have cheat codes that change the appearance of the characters, like the Easter Eggs do.

Modes
Pressing the ? key will bring up the "Easter Egg Menu". The menu shows the following options:

47 Mode

 * Main Article: 47 Mode


 * L key to activate 47 Mode. This mode will make Yandere-chan bald, have a barcode on the back of her head, and change her shirt to a black jacket with a red bow. This mode is a reference to the Hitman series.

AI Mode

 * Main Article: AI Mode


 * Space key to activate AI Mode. This mode is a reference to Kizuna AI, a Japanese virtual YouTuber. Yandere-chan's model will be replaced with Kizuna AI's model. If the Space key is pressed again, Kizuna will change her facial expression. It is not listed in the Easter Egg menu.

Bad Romance Mode

 * Main Article: Bad Romance Mode


 * Collect all eight stationary objects and then press the Left CTRL key while standing on the rooftop to activate Bad Romance Mode. This mode is a reference to JoJo’s Bizarre Adventure, as Bad Romance is Yandere-chan's Stand. If the Left CTRL key is pressed, Bad Romance will throw a rapid flurry of attacks, emulating the fighting style most commonly utilized by Stands in JoJo's Bizarre Adventure.

Bad Time Mode

 * Main Article: Bad Time Mode


 * U key to activate Bad Time Mode. This is a reference to the popular game Undertale. Yandere-chan will resemble the character Sans from said game. If the Left CTRL key is pressed, she will be able to use his attacks from the fight in the Genocide Route of the game to kill NPCs.

Bancho Mode

 * Main Article: Bancho Mode


 * B key to activate Bancho Mode. This gives Yandere-chan bandaged arms, a black school outfit, a Sergeant cap, and a blade of grass in her mouth. This mode is a reference to Mako's Two-Star Goku Uniform from the anime Kill la Kill.

Blade Hair Mode

 * Main Article: Blade Hair Mode


 * 6 key to activate Blade Hair Mode. Yandere-chan will have bright pink twin tails with blades at the bottom. Pressing the Left CTRL key button will cause Yandere-chan to spin rapidly. NPCs that touch Yandere-chan's hair will be dismembered instantly.

Cirno Mode

 * Main Article: Cirno Mode


 * C key to activate Cirno Mode. This mode is a reference to Cirno, from Touhou. Yandere-chan's outfit and hair will become blue, and she will resemble Cirno. Pressing the Left CTRL key button will make Yandere-chan shoot ice out of her hands, killing any NPC they touch.

Cyborg Mode

 * Main Article: Cyborg Mode


 * Y key to activate Cyborg Mode.  This mode cannot be deactivated until the game is reset or the day changes. Yandere-chan's uniform will change into a black cyborg suit with a neon blue visor. She will also acquire a long silver ponytail and an Energy Sword that can be used to dismember students and teachers. Yandere-chan will run faster than normal. Pressing "P" will take off the helmet.

DK Mode

 * Main Article: DK Mode


 * K key to activate DK Mode. This mode will enlarge the head and arms of Yandere-chan and every NPC with a working AI. This is a reference to a cheat of the same name and function from the video game GoldenEye 007.

Ebola Mode

 * Main Article: Ebola Mode


 * E key to activate Ebola Mode. Yandere-chan will become deathly pale with pink pigtails that resemble the Ebola virus, a reference to Ebola-chan. Any student she touches will instantly die (presumably from Ebola), including Senpai.

Falcon Mode

 * Main Article: Falcon Mode


 * F key to activate Falcon Mode. Yandere-chan will don a full body outfit of Captain Falcon, the main character of F-Zero. Pressing the Left CTRL key will make Yandere-chan punch forward very fast, sending anyone on her way with a proper AI flying up into the air. She also runs very fast.

Galo Mode

 * Main Article: Galo Mode


 * G key to activate Galo Mode. It gives Yandere-chan tanned skin, gold bracelets, sunglasses and Super Saiyan hair. Pressing the Left CTRL key will make Yandere-chan "power up", but her reputation will be affected if she's seen by students.

Gazer Mode

 * Main Article: Gazer Mode


 * 1 key to activate Gazer Mode. It is a reference to Gazer. Yandere-chan will have light gray skin and black goo down her body. Press the E key to kill NPCs in several different ways, depending on the floating eyes' color.

Hateful Mode

 * Main Article: Hateful Mode


 * H key to activate Hateful Mode. It is a reference to Hatred, and its main character, "The Antagonist". Yandere-chan's uniform and skin will become monochrome, as well as the screen. Sanity levels will set the to minimum.

Hunger Mode

 * Main Article: Hunger Mode


 * 6 key to active Hunger Mode. It is a reference to the video game Little Nightmares. Yandere-chan will wear a yellow raincoat with a triangular hood. She can eat people and gain speed.

Huntress Mode

 * Main Article: Huntress Mode


 * Q key to activate Huntress Mode. It is a reference to Samus from the Metroid series. Yandere-chan will wear a blue body suit, have blonde hair and green eyes, and will have a mole under her lower lip.

Lightsaber Mode

 * Main Article: Lightsaber Mode


 * D key to activate Lightsaber Mode. It is a reference to Star Wars. Yandere-chan will wear a long black dress with a hood, she will frown and hair will cover her left eye. When the CTRL key is pressed she will get lightsabers, if F is pressed she will attack.

Medusa Mode

 * Main Article: Medusa Mode


 * M key to activate Medusa Mode. It is a reference to Medusa from Greek Mythology. Yandere-chan will resemble Medusa and have hair made of green snakes, her uniform will have a green color scheme. If a student looks at Yandere-chan, they will turn to stone.

Punch Mode

 * Main Article: Punch Mode


 * O key to activate Punch Mode. Yandere-chan will become bald and don the full body outfit of Saitama from One-Punch Man. When the Left CTRL key is pressed, she will use his iconic punch. Any student hit will go flying.

Punished Mode

 * Main Article: Punished Mode


 * P key to activate Punished Mode. This mode is a reference to the video game Metal Gear Solid V: The Phantom Pain. It gives Yandere-chan a torn-up version of the original Akademi High School outfit, a tan-colored scarf, a black eyepatch on her right eye, a red left arm, a scar on her left eye, a black protrusion from her forehead, a black glove on her right hand, and a cigar.

Slender Mode

 * Main Article: Slender Mode


 * Z key to activate Slender Mode. This mode makes Yandere-chan's uniform turns a very dark gray, her skin turn completely white, her eyes turn blank, and her body shape resembles that of the Slender Man. Activating this mode sets Yandere-chan to minimum sanity level. This mode was created because it was very easy to stretch out Yandere-chan's limbs.

Spooky Mode

 * Main Article: Spooky Mode


 * S key to activate Spooky Mode. This mode turns all female students and teachers into skeletons.

Titan Mode

 * Main Article: Titan Mode


 * T key to activate Titan Mode. This mode is a reference to Attack on Titan. It will remove the students' clothing and skin and make them increase greatly in size. It will also change the blue parts of Yandere-chan's uniform to brown. This mode's name may be changed to Colossus Mode at some point.

Tornado Mode

 * Main Article: Tornado Mode


 * 7 key to activate Tornado Mode. This mode is a reference to the One-Punch Man character Tatsumaki. In this mode Yandere-chan will have messy pink hair and a long white dress. Pressing the Left CTRL key will summon tornadoes that will kill NPCs.

Witch Mode

 * Main Article: Witch Mode 

W key to activate Witch Mode. This mode is a reference to Bayonetta (Cereza) the main protagonist of the Bayonetta series. It does not show up in the Easter Egg menu. Yandere-chan will have her default black ponytail, red lipstick and she will wear a black body suit.

X Mode

 * Main Article: X Mode


 * X key to activate X Mode. This mode turns Yandere-chan into /x/-tan, a personified mascot of 4chan's /x/ Board. She has rainbow stockings, black hair, an eyepatch on her left eye, black underwear, and a black tank top with a skull on it. Pressing the Left CTRL key will cause Yandere-chan's hair to change to the Hateful Mode hairstyle and will remove the eyepatch, revealing a glowing red eye.

Yandere-kun

 * Main Article: Yandere-kun


 * 8 key to activate Yandere-kun. This mode turns Yandere-chan into Yandere-kun. This mode can be combined with other Easter Eggs, however, Yandere-kun will wear his uniform beneath the Easter Egg outfit.

Yanketsu Mode

 * Main Article: Yanketsu Mode


 * 4 key to activate Yanketsu Mode.  This mode is a reference to Kill la Kill. This mode cannot be deactivated until the game is reset or the day changes. Yandere-chan's uniform will change into a revealing white, blue, and pink outfit. She will also acquire a Knife Blade that can be used to dismember students and teachers.

Long Skirt Mode

 * V key to activate Long Skirt Mode. This will make Yandere-chan and the female delinquents wear long blue skirts that go to their ankles. There is no real name for this mode yet. It does not show up on the Easter Egg menu. YandereDev has the mode because it "allows him to test out a 'dress' character model so that he can look for bugs."

Naked Mode

 * N key to remove clothes. This will make Yandere-chan nude. It does not show up on the Easter Egg menu.

Gravity on Corpses Disabled

 * I key to disable the gravity on corpses. This will make all corpses and dismembered limbs fly away. This only works on students or faculty members killed after the easter egg has been enabled.

Security Camera Heads
If the players presses 3, female students' and faculty's heads will be replaced with large security cameras.

KON Mode

 * KON mode is an Easter Egg which the player cannot activate without modifying the game. It is unknown why YandereDev has not added the option to activate this Easter Egg. It has been around since the March 3rd, 2015 Build. This is a reference to the anime K-On!.

Phantom Girl

 * Main Article: Phantom Girl

If Yandere-chan takes a picture in the bathroom on the third floor, a semi-transparent girl about the size of an average student model will appear in the picture. No matter where Yandere-chan is, the ghost will be looking in her direction.

Demonic Ritual

 * Main Article: Demonic Ritual

As of the February 21st, 2016 Build, a ritual knife has been added to the altar in the Occult Club room. Killing a student with it and then putting it back in the altar will transport Yandere-chan to a dark void, where three figures stand in a circle. The player can converse with each of them.

Starting Screen
After about ten seconds, the title screen will show the darker side of the game for a short amount of time, including a dark atmosphere, a bloody uniform, and squirming corpses. Pressing the Space Bar can manually change to the "insane" title screen, but only for a short amount of time. Tapping the space bar repeatedly will make it last longer.

The player can also press F1, F2, F3, F4, or F5 to change the students' uniform on the main menu screen.

In an older version, the starting screen had different animations every ten seconds, such as Yandere-chan stabbing a student rapidly, being covered in blood while carrying a severed head, and staring blankly at the viewer. The only sound played during these scenes was static.

Opening Screen
As of the November 1st, 2015 Update, pressing the Y key on the opening screen will start Yanvania: Senpai of the Night as if the player had gone to Yandere-chan's room at night to play it. When Yandere-chan finishes the game, it will end with the afterlogue and the disk error as normal, and the player will be in Yandere-chan's room in the morning in pajamas instead of her uniform.

Easter Egg Students
Ryuto Ippongo, Pippi Osu, Midori Gurin, Mai Waifu, Kuu Dere, and Fureddo Jonzu are all references to various characters in media.

Gaming Club
Ryuto is based on Ryuta Ippongi from Osu! Tatakae! Ouendan, Pippi is from a fangame of Ouendan called Osu!, Midori is based on Churuya from Haruhi Suzumiya' and fans who email YandereDev constantly, and Mai Waifu is based on YandereDev's dream anime girl.

Other
Fureddo is based on Fred Jones from Scooby-Doo and Kuu Dere is based on Rei Ayanami from Neon Genesis Evangelion.

Video Game Easter Eggs
There is an Easter Egg in Yanvania: Senpai of the Night. If the player presses M on the title screen, Midori Gurin will pop out from the right side of the screen and the afterlogue will start in her voice. The disk error will occur after she is finished.

Storage Room Easter Eggs
The following Easter Eggs can be found inside the northeastern storage room on the first floor.

Bunny Ears
On a shelf at the right side of the room, lays white long bunny ears, Samgladiator`s accessory. When picked up, Yandere-chan will wear it until the day ends or is restarted.

Saikou Company Cardboard Box
There is a cardboard box inside the room that Yandere-chan can "hide" in. This is a reference to the cardboard box stealth mechanic in the Metal Gear series. The player can remove it by pressing the Left Control key.

Carrot
On a shelf at the right side of the room, there is a carrot, a reference to Veggie Gamer`s channel logo. When picked up, Yandere-chan will hold it in her mouth until the day ends or is restarted.

Cheese
There is a piece of cheese near a mouse hole at the bottom of the room. When examining the piece of cheese, words will come up on the HUD, saying, "Knowing the mouse might one day leave its hole and get the cheese...It fills you with determination." This is a direct reference to a line from Undertale.

Crush
There is a golden C on one of the shelves, which is a reference to Crush Crush. When interacted with, Yandere-chan's model will resemble the girls from Crush Crush.

NGB Bear

NGB Bear can be activated with the A key.This is a reference to  a YouTuber who has been making Yandere Simulator videos for a long time.



NyanDroid

NyanDroid can be activated with the A key. This is a reference to TheNyanCave. When activated, it will follow Yandere-chan around until the day ends or is restarted.

Pink Mustache
On a shelf at the right side of the room, there is a fake pink mustache. This is a reference to Markiplier. When picked up, Yandere-chan will wear it until the day ends or is restarted.

Poem
On a shelf to the left side of the room, there is a poem by Laina Morris. This is a reference to the game "Doki Doki Literature Club!". When interacted with, Yandere-chan will resemble the girls from "Doki Doki Literature Club!".

Scrub-chan
On a shelf at the right side of the room, there is a lime green puppet with a leaf sprout who resembles Scrub-chan, Bijuu Mike's mascot. When picked up, it will be placed on Yandere-chan's left shoulder until the day ends or is restarted.

THAT DUDE Sunglasses
On a shelf at the right side of the room, there is a pair of sunglasses with the word "THAT" on the right lens and "DUDE" on the left lens. This is a reference to Jay from the Kubz Scouts. When picked up, Yandere-chan will wear it until the day ends or is restarted.

Ancient Evil
If the player goes behind the tree on the left when entering the school, they will have the option to summon the Ancient Evil, which can be used to activate or deactivate students and teachers.

Book
At various times each day, Kuu Dere, Senpai, and Horuda Puresu will walk to their respective places and read a book. Study-kun B will also read the same book in the library. This book contains simple information on Yandere Simulator's premise.

The last paragraph is a reference to the Undertale game file, "abc_123_a.ogg", in which listeners are asked not to spoil the game for others.



Confession Tree Voice
If the player steals Sakyu Basu's ring at lunchtime and then goes to the Confession Tree behind the school, a female voice will say "...that...ring...".

Delinquents
Between the April 15th, 2017 and April 26, 2018 builds, if the player pressed the Space Bar ten times in front of the placeholder delinquents, they donned Team Skull masks and danced slowly.

Fun.txt

 * Main Article: Fun Girl

The Fun.txt was added into the Streaming Assets folder as of the February 8th, 2016 Build. Within the text was a single zero, which the player could change. Depending on the number entered, there would be several texts before the game usually crashes. Deleting this file does not have any effect on the game and it will run as normal. The file was removed in the January 4th, 2017 build, and readded in the April 2nd, 2018 Build.

Glowing Blue Eye
The left eye of the skull in the Occult Club will glow blue after viewing the cheese. This is another reference to Undertale, namely the character Sans, whose left eye also glows blue.

Pink Turtle
If the player goes to Mr. Jazzy Feet in the Light Music Club and asks him to forgive their sins several times, a pink turtle wearing a bow will appear alongside Mr. Jazzy Feet in his tank.

Rainey
If the player types out the word 'rainey' on their keyboard, a female student will appear in the Martial Arts Club just behind where Budo Masuta stands. She will wear the default uniform regardless of customization and has a long brown braid. She will slowly sway side to side.

Front Page

 * If the Konami code (up, up, down, down, left, right, left, right, B, A) is entered on the main page, the website will become red and black instead of a light pink.

Characters Page

 * If the Konami code is entered on the characters page, the website's theme will become dark. All the current characters' profiles will be replaced by a profile of the Fun Girl. Her role, status, personality, appearance and weakness will all be "?????". If the player hovers over her image, the page will start to turn to static and eventually the screen will go black. The kanji text on the left says:

Which translates to:

Bugs

 * In DK Mode, it is difficult to mop up blood because the mop grows and moves through the floor when the player picks it up.
 * Long Skirt Mode will not work correctly for any uniforms besides the default one, as it glitches the textures.
 * If the player kills all the teachers and students in the school with an Easter Egg mode, at the end of the day, the game will still say that a teacher discovered a corpse.

Trivia

 * If it becomes possible to choose Yandere-chan's gender, then male-equivalent Easter Eggs will have to be created.
 * There may be an Easter Egg where one NPC is secretly a magical girl, and there would be an opportunity to see her transform. It's a low priority, however.
 * In addition, if Yandere-chan manages to collect all ten Magical Girl Miyuki manga, she will unlock a magical girl Easter Egg.
 * C was used to disable copyrighted music. With Cirno Mode now available, it has been shifted to D. M also mutes the game music.
 * YandereDev's favorite Easter Egg to create is Punished Mode.
 * There may be a Sonic Easter Egg where Yandere-chan is naked, covered in blue body paint, and moves at 10x speed.
 * NPCs without an AI are not affected by any mode.
 * It was very important to YandereDev that some sort of cheat code or Easter Egg in the future will unlock a "giant sci-fi energy scythe". It was later revealed to be the Cyborg Mode.
 * In the game's code, Info-chan's glasses are named KON glasses.
 * Undertale has been referred to the most through Easter Eggs, with its references being the mouse hole and cheese, the skull with its glowing eye in the Occult Club, Bad Time Mode, the Fun Girl, and the book students read.