A cute…ish and fairly complex game about the life of Yandere-chan (a placeholder name, obviously) and how you, as the player, must help her sabotage her rivals for Senpai's affection. It's still in its debug builds, but another update will be released as early as tomorrow according to the dev blog. There are expected to be various methods of sabotaging your rival, from kidnapping her via knocking her out by tranquilizer (only if your biology grades are high enough, and you'll have to get past the school nurse as well in later builds), to straight up stabbing her in the neck and dumping all evidence in the incinerator, to sabotaging her online or real life reputation and potentially causing her to commit suicide.
The guy behind this seems fairly competent and friendly. Personally, I like yanderes and even if I didn't, the game is actually challenging and interesting enough (if not in theory for now) to make me interested. Obviously, if you're sensitive to blood, gore, psychological torture, and all that other fun stuff this isn't the game for you - but considering this board, I doubt there's much of a problem.