Obi is one of Zen's self-proclaimed aides.

Originally sent by Marquis Haruka as a way to scare Shirayuki out of the castle, he later pledges himself to Zen after being discovered.

It is hinted that he has feelings for Shirayuki, but his loyalty to both Zen and Shirayuki prevents him from acting out on his feelings.

Obi has a relatively mysterious past as a loner, but finds himself drawn to protecting Zen, Shirayuki, and their respective goals. He is often sent by Zen to protect Shirayuki when Zen is unable to leave his duties.

He has been seen using the alias "Nanaki".