Nishinosuke Akai

赤井西之介, Hacchoubori

A plain-clothes police sergeant for the city of Edo. He hates everyone in the house complex where Sora resides, especially Gin.

He later turns to murder to feed blood to the blue sky beast (Yu), with whom he is having a sexual relationship, and eventually agrees to help her find her way back to the moon before Sora.