"Yandere Simulator is a stealth game about stalking a boy and secretly eliminating any girl who seems interested in him, while maintaining the image of an innocent schoolgirl. ... The gameplay is similar to the Hitman series; you are put into a large environment filled with many NPCs, and you must track down a specific target and eliminate them. You can use stealth to kill your target without any witnesses, stage an accident that leaves no evidence, or just slaughter anyone who gets in your way. If you don't dispose of corpses, clean up blood, and destroy evidence, then the police might be able to link you to a murder and arrest you." [1]
The game is notorious and often meme'd on for its long development cycle, primarily due to the fact that the developer YandereDev (Alex Mahan) often sidetracked his work to other things, such as streaming and vtubing, as well as several controversies surrounding it. As such, the game is still under development as of date.
Note: The names of the characters are puns on anime culture and chosen for commonality, thus their names are not meant to be rendered in Eastern order.