Easter Eggs

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

YandereDev has included some 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 of 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". Pressing D will disable the copyrighted music for Punished Mode, Galo Mode, 47 Mode, Bad Romance Mode, and Falcon Mode. 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. The music is replaced by "Only You Can Stop Them" by Jesper Kyd from the game Hitman - Blood Money. This mode is a reference to the Hitman series.

Bad Romance Mode

 * Main Article: Bad Romance Mode


 * J key to activate Bad Romance. This mode is a reference to JoJo’s Bizarre Adventure, as Bad Romance is Yandere-chan's Stand. In the future, Bad Romance will throw a rapid flurry of attacks as soon as someone builds a control rig for it, in order to emulate the fighting style most commonly utilized by Stands in JoJo's Bizarre Adventure. This mode has since been removed.

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. She will be able to use his attacks from the fight in the Genocide Route of the game to kill students and teachers. An original song plays the entire time in this mode.

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.

Cirno Mode

 * Main Article: Cirno Mode


 * C key to activate Cirno Mode. This mode cannot be deactivated until the game is reset or the day changes. This mode is a reference to Cirno, a popular character from Touhou. Yandere-chan's outfit and hair will become blue, her skirt will change to look like the bottom of Cirno's dress, and white "ice" wings will grow out of her back. An original song plays the entire time. The player flies around everywhere, and pressing the Control button will make Yandere-chan shoot ice out of her hands, killing any student from far away, provided there isn't any obstacle in her path.

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. Pressing "P" will take off the helmet. An original song made by DamProgMusic will play the entire time. Yandere-chan will run faster than normal.

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 GoldenEye007. This mode can cross over with one other mode, but after that the game must reset or the day must change to reset the mode.

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 Control will make Yandere-chan punch forward very fast, sending anyone in her way with a proper AI flying up into the air. The song used in this mode is "Big Blue" from Super Smash Bros Melee and Super Smash Bros Brawl. She also runs very fast, making it slightly difficult to move around in tight spaces.

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. It also replaces the music with "Galo Sengen" by Policeman110. Pressing the Control button will make Yandere-chan "power up", but her reputation will be affected.

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 screen will turn into a monochrome scheme. Metal music plays the whole time in this mode. As with Slender Mode, this will set the sanity level to minimum.

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.

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. She will be able to use his iconic punch. Any student hit will go flying. A song called "Unknown Hero" from The Kira Justice will play in the background the entire time.

Punished Mode

 * Main Article: Punished Mode


 * P key to activate Punished Mode. This mode is a reference to Metal Gear Solid 5. 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. It also replaces the music with an original song made by DamProgMusic.

Slender Mode

 * Main Article: Slender Mode


 * Z key to activate Slender Mode. This mode makes Yandere-chan's uniform turn a very dark grey, her skin turn completely white, her eyes turn blank, and her body shape resemble that of the Slender Man. Suspenseful music plays the whole time while in this mode. Activating this mode sets Yandere-chan to minimal 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 and plays Nyanners' cover of "Spooky, Scary Skeletons" by Andrew Gold in the background.

Titan Mode

 * Main Article: Titan Mode


 * T key to activate Titan Mode. This mode cannot be deactivated until the game is reset or the day changes. 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. If Yandere-chan kills someone and then turns this mode on they will turn into regular-sized corpses. This mode's name may be changed to Colossus Mode at some point.

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.While killing students her outfit will get darker and darker.

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 leggings, black hair in Midori's former style, an eyepatch on her left eye, black underwear, and a black tank top with a skull on it. Suspenseful music plays the entire time. Pressing Control while this mode is activated will cause Yandere-chan's hair to change into the Hatred hairstyle and will remove the eyepatch, revealing a glowing red eye.

Naked Mode

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

Long Skirt Mode

 * V key to active 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."

KON Mode

 * KON mode is an Easter Egg which the player cannot activate without modding 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! . This was previously a uniform the player could choose to wear in the original intro. As it stated, "This uniform would be perfect for a girl who wants to join the Light Music Club!"

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.

This character used to be near the Confession Tree behind the school for testing purposes. If Yandere-chan ran into her, her uniform changed into a red and black color scheme. The outfit change was later removed because many people mistook it for a bug and complained. She was eventually moved to the bathroom, because that was where she was originally killed in 1989.

YandereDev says that people must customize the uniform texture if they wish to have the uniform back.

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.

If the player completes the Pain Demon's ritual, they will gain the ability to dismember everyone but Senpai, the Substitute Nurse, Rival-chan, the Placeholder Club Leaders, and the delinquents in front of them using ten hands.

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, and Kuu Dere themselves are Easter Eggs.

Ryuto is based on Ryuta Ippongi from Osu! Tatakae! Ouendan, Pippi is from a fangame of Ouendan called Osu!, Midori is based on the character Tsuruya from The Melancholy of Haruhi Suzumiya, Mai Waifu is based off YandereDev's dream anime girl, and Kuu Dere is based on Rei Ayanami from Neon Genesis Evangelion. All of them except for Kuu Dere are in the Gaming Club.

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.

Cheese
There is a piece of cheese near a mouse hole in one of the storage rooms to the east of the entrance. It is near the back of the school, to the left of the Meeting 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.

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...".

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 can change. Depending on the number imputed, there will 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. In Undertale, tampering with the "Fun" Value will cause Gaster, the royal scientist to appear. Likewise with the Fun Girl, they were both shattered across time and space when an invention went wrong.

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.

Bugs

 * Some decoration Easter Eggs obstruct the camera view, such as Bancho Mode. YandereDev is aware of this bug and will not respond to any emails of it.
 * 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.
 * Pressing C 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 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, such as the placeholder nurse, Genka Kunahito, placeholder club leaders, delinquents, and Rival-chan, are not affected by any mode.
 * It is 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 referenced the most through Easter Eggs, with its references being the mouse hole and cheese, the skull with its glowing eye in the Occult Club, and Bad Time Mode.