A member of the Togoru team in the dark tournament. Karasu is a lower B Class demon. Karasu's personality is largely unknown, with Karasu always remaining calm and serious, never showing his true self. Karasu always wears a mask over his lower face. His goal in the tournament was to have Kurama's severed head. In the second Character Popularity Polls in Japan, Karasu was at 8th place with 698 votes, making him the most popular member of Team Toguro.

Sometime ago, Karasu and Bui faced off against the Toguro brothers, where the brothers won. Promising them a rematch if they joined their force, the two followed the Toguro Brothers.

Karasu is a demon bomber, and as such can not only explode things without physical contact, he can also create bombs himself, including winged bombs and giant cases of dynamite. Karasu's most dangerous ability comes after he removes his mask, and his hair turns from black to blond, a full-body explosion strong enough to kill large numbers of humans.

Before the Final Rounds, Karasu met Kurama in an alley where the two had a confrontation, which ended in Karasu victorious.

During the Final Rounds, Karasu fought against Kurama, where he almost killed Kurama off rather quickly, and it was only thanks to a potion Suzuka gave to Kurama that helped him live, transforming him into Youko. Kurama then gained the advantage, having a giant plant eat Karasu. Karasu simply exploded the plant and used his full-body explosion on Kurama, reverting him back to human. Karasu then had the complete advantage, almost killing Kurama, but Kurama used a Vampire Plant to stab Karasu's heart, killing him. However, Kurama still failed to win the match since he attacked from his knees and timed out.