Grimm

Takumi's online friend, who talks to him almost everyday through their mutual favorite online game. He often encourages Takumi to have more courage while dealing with the "third dimension", and supports him throughout his many ordeals. He is very interested in the New Generation incidents and frequently updates Takumi with gory details regarding the murders. As his interests in anime, manga, and games are very similar to Takumi's, the two get along very well.

Spoiler

It is revealed later that Grimm is a she, as well as one of the New Generation culprits.