Excluding Ayano Aishi, there are 79 students currently implemented. There was plan of about 90 or more students, but the target has been lowered to 88, due to Mida Rana and Muja Kina both taking up student spots.
Before the September 15th 2019 build, Horuda Umetsu was a temporary placeholder girl but since Yandere Dev changed her to a permanent student, as of the September 15th 2019 build, there are no more temporary students.
Most students follow a specific routine. Currently, the only implemented students that do not have a specific set routine are Ayano Aishi, Info-chan, the Phantom Girl, and NPCs with no AI.
The original delinquents were replaced in the April 26th, 2018 Build. They may appear in 1980s Mode according to YandereDev. In one of his videos, it was shown that they went into some sort of time machine.
Red Flower was the 6th member of the Gardening Club and was later removed in the July 1st, 2018 Build due to the club being fully implemented. The other members have updated hair colors and names, but remain in the club.
The "Rainbow Twelve" male and female students were also removed in the August 18th, 2018 Build. Out of both groups, only Riku Somatomo, Saki Mayuzumi, and Kokona Harukawa remain in the game. It was decided that they should be removed since the framerate improves without them, but they may come back in the future. The 4 rainbow girls who were removed from the school now appear in the town as normal pedestrians walking around.
Study-kun A and Study-kun B were removed in the January 1st, 2019 Build as they are no longer needed to show attraction from a rival.
Rival-chan was officially removed in the July 18th, 2019 build and replaced by Raibaru Fumetsu, who has the same appearance.
Although they are removed, YandereDev stated that they might be added in 1980s Mode. He might also add them back if the framerate significantly improves. He might add a cheat code to spawn them and use the rivals' slots, but it will be removed once the rivals are implemented.
These characters have only appeared in their respective games. Sakura appeared in Burning Love, Tsundere-chan and Kuudere-chan in Kuudere Simulator, Himedere-chan in Kuudere Simulator 2, and Osana Najimi in Kuudere Simulator 3.
Students sometimes get stuck on each other or the props.
Since Budo Masuta is no longer one of the suspects of Osana Najimi's suitor, he may be the suitor of Raibaru Fumetsu.
There may be a Kickstarter reward allowing a fan to create a student to be implemented into the official game.
It may be possible for the player to add their own students in the future.
There will be one character in Yandere Simulator who YandereDev has always envisioned as someone who tortures animals. However, it is not Ayano.
If YandereDev could make a student based on himself, he would make a student who is in the Gaming Club, a Loner, and has no crush, unless he added a student who resembles his favorite video game character. Still, he has no desire to put himself in-game.
An NPC with Rival-chan's appearance was said to possibly be in the final game, this turned out to be Raibaru Fumetsu.
There may be a student that looks like YandereDev, but is the complete opposite of him otherwise.
YandereDev would love to include a gothic lolita character.
Students with something noteworthy about them (such as rivals and Easter Egg students) might have ironic names.
In the future, when a student who wears glasses loses their glasses, their line of sight might be reduced.
There is a reason why the students will still come to school when they know there is a serial killer on the loose, but YandereDev has not released this information yet.
In very early debug builds, all students were recolors of Ayano's model, with the only difference being the hair and eye color (dark blue). Before students had names, they were all named "Student-chan" within the game code. They were given different hair colors in the February 15th, 2015 Build. Five corpses of "Student-chan" used to be seen on the title screen before the March 17th, 2016 Build, when they were changed.
YandereDev quickly makes students by modifying lines on an XML sheet and exporting the XML as a JSON file. Within the current game engine, however, he has to place all physical destinations where a student has to go. In the future, the game will automatically assign students' destinations.
There will be some comic relief moments in the full version of Yandere Simulator, during particular NPC conversations.
Some boys in the school are very big perverts, as they buy panty shots from Info-chan.
In the future, two "special" NPCs that are popular among fans may enter a relationship.
The player may be able to distract students with small firecrackers in the full game.
As of the September 20th, 2015 Build, students' clothes, hair, and animation codes are not active when Ayano is far away. This is to improve the frame rate.
Since Info-chan is a notorious name around the students, her default reputation will be -999. But her true identity will have a rep of "0", as no one knows who she really is.
The names of the first six male and six female characters are the most popular Japanese given names of 2012.
Pippi and Ryuto will be the only rhythm game references in Yandere Simulator.
A fictional anime called Magical Girl Pretty Miyuki will be popular among students, and they may talk about it occasionally. "Did you see last night's episode of Magical Girl Pretty Miyuki?"
YandereDev stated that he might even add a magical girl in the game for fun.
Budo Masuta is the only fully programmed NPC who doesn't appear to be scared at low School Atmosphere. However, if the Martial Arts Club closes down, he will become paranoid.
YandereDev will only make parodies of characters that he cares or knows about.
YandereDev has stated that a Japanese teacher told him nobody at school would be openly LGBT and only come out after graduating.
However, Senpai, Ayano, Yandere-kun, and the rivals will not be straight depending on what combination of those characters the player chooses.
YandereDev "has some plans for students who act as amateur 'investigative journalists'". These students turned out to be the Photography Club.
In the future, the delinquents will only willingly interact with the player if Ayano's reputation is low enough. They will not help the player with murder nor take the blame for it.
Currently, the only student's (With the exception of Kuu Dere, Horuda Puresu, Kyuji Konagawa, Otohiko Meichi, and Hazu Kashibuchi) purpose in the game so that they will easily witness Ayano commit murder, as they always patrol the school.
In the future, it's possible that if Ayano gets too popular, some students may start to stalk her, meaning that any murders committed would have witnesses.
According to YandereDev, Ayano would only befriend students for manipulative purposes.
YandereDev would love to keep the original 12 students in the game, but he might have to ditch some NPCs if the production puts limits on him. As of the August 18th build, 9 of them were removed.
There are two characters who have abused an animal once during their life. It is unknown if these characters are students or not.
YandereDev would like to rename some characters.
YandereDev may have the female students in the game act more like "real Japanese schoolgirls" and perform lewd actions such as sneaking up on another girl and pulling up her skirt. He was most likely kidding when he mentioned this.
YandereDev hopes to implement the ability to put custom skin and uniforms on students in the future.
In the future, students will be programmed to carry their book bags.
In the final game, it is almost certain that all students will be the same height.
Originally YandereDev stated that there would be at least one exchange student and that they would most likely be American so the student could be a comically exaggerated American stereotype.
However, YandereDev has since stated that he does not think he'll add an exchange student.
YandereDev has hinted that one of the current students may have multiple personality disorder.
If the S key is pressed in the debug menu, looking at the second reserved student slot displays a profile with ‘Invincible’ self-defense, and the ‘Protective’ persona. That student was later revealed to be Raibaru Fumetsu.