Yandere-kun

Yandere-kun is a non-canon character, however he is not an OC. He is the male counterpart of Yandere-chan. He is what the player character would be, if a male Yandere-chan was implemented. However YandereDev does not plan to due to the extra coding work and the fact that he finds male yanderes to be distasteful.

Don't Notice Me, Senpai!
He is yandere for Natsumi and Natsumi has feelings for him also, due to his seemingly kind nature.