Shouji Kazuma

The number two of the 'Yomi' Shinigami company, Renji's right hand man.
A friend of Renji who has known him since his school days.
He has the blood of an oni and is very strong.
He's affectionate towards the protagonist because she is the daughter of his friend, but it doesn't seem like he feels anything more than that...

Spoiler

He has a non-romantic ending in the main game.