Hanako is a short boy with dark hair and large amber eyes. He wears an ancient black gakuran and has an exorcist's seal on his left cheek. It is also usually seen accompanied by two spirit spheres named Haku-Joudai. (Source: Hanako-kun Wiki)

Monokuma is the main antagonist of the series. A strange, remote-controlled teddy bear who proclaims himself to be the principal of Hope's Peak Academy and initiates a life of mutual killing amongst the students. He has various copies of himself throughout the Academy and will punish, ie. kill, anyone that attempts to attack him or otherwise break the academy's rules. Much like his name, he has a monochrome appearance, with one half looking like a cute white bear and the other half looking like a sadistic black bear. Just who the mastermind controlling him is, along with his motives for bringing the students together, serve as some of the game's main mysteries. (Source: Wikipedia)