Kuro

The yandere hero of the otome game Solipsism Reigns. Very protective of the heroine protagonist, gets jealous easily. He has a tendency to resort to extreme violence when his switch is flipped, whether that be towards people he sees as possible love rivals, or the protagonist herself.

He can be very sweet and loving, the protagonist is his world. He would do anything for her, but sometimes can't control his urges to hurt her when he's emotionally compromised. He often expresses regret after killing her.