Monochrome Factor

Synopsis

Akira Nikaido is an easygoing student whose life is about to change after an encounter with a stranger who knows his name. The man, Shirogane, does not possess a shadow and explains that this is because he is a shadow himself. Shirogane then disappears, making Akira think he might have been a ghost. Later that night, Akira's friend Kengo drags him out to 'enjoy' the night at an arcade. There, they save a young child named Haruka and his butler from bullies. Afterwards Aya, the school prefect, finds them. In exchange for not beating them up, she asks for a favor: accompany her to their school so she can pick up something she forgot. They go there and, after getting the dragon plushie she forgot, they start walking back outside – only to be attacked by shadow monsters. Aya accidentally beats Kengo and faints when her plushie's head is severed by a shadow's blades. Akira tries to ward the shadows away with Aya's sword but it gets destroyed. Shirogane appears to lend his aid by creating a barrier. He explains that the shadows are called "kokuchi". Confused, Akira runs through the barrier, only to sink into the ground and looses his shadow. Shirogane saves him and explains that if he remains shadowless, Akira will die but can be saved if he makes a deal with him. Akira agrees and Shirogane kisses him, turning him into a Shin (shadow being) which gives him special powers (Shin form: dark haired version of himself with different clothes and 2 daggers). The next morning, the fight is finally over and Akira asks Shirogane how to be human again. Shirogane explains that he can't and also normal people can't see him. Kengo and Aya arrive and Shirogane vanishes, leaving a confused but normal Akira behind.

(Source: Wikipedia)