Saeki Enishi

"Rely on those around you more. It's hard to live if you're always stubborn."

Mashiro and Yuu's classmate. His family were demon exterminators for many generations, but retired in his grandfather's generation. Therefore, his knowledge on demon extermination is thin. He is loved by his siblings as a reliable older brother.

He is good at reading the mood and has many friends. He's especially close to Yuu, and they confess their troubles to each other.