
Break the Cutie: He has close relationships with two of the rivals ( Osana Najimi and his younger sister), and the developer has stated that the way they disappear from his life may give him serious mental problems by the end of the game, including PTSD. He has black hair by default and is frequently seen reading a book at the fountain during the morning, implying that he's a bit of a bookworm, but if Info-chan's comments in the Student Info are anything to go by, his grades (like everything else about him) are average. Blessed with Suck: He has the ability to instantly attract a harem of girls who all want to be with him. At first only the most average girls will like him, but each subsequent rival is more popular, important, strong, or otherwise difficult to defeat than the previous one. Big Brother Instinct: It's implied that he will have this to his little sister once she's implemented in the game. Beware the Nice Ones: YandereDev states if he's pushed too far and he finds out that Yan-chan was the cause of all his torment, it doesn't end well as we see Senpai grab a knife. Berserk Button: He finds people who commit crimes while wearing masks to be especially cowardly, and will attempt to rip your mask off if you kill someone in front of him wearing a mask, even at the expense of his own safety.
Bald of Awesome: One of the hairstyles you can give him on the customization screen.Author Avatar: In Fall 2015, became one of YandereDev for a while (replacing Ayano), until Dev got his own unique avatar that looked somewhat different from Senpai several months later.He ( or she, eventually) is around 18 years old, has a "Loner" personality, and is in Class 3-2.
Senpai is a regular senior-year student at Akademi High who inadvertently becomes the target of affection for Ayano-chan and nine other females at the school note (his little sister Hanako, while still a rival, has a completely different motive).