Tomoe Shinjo

Age: 26

Later: 27

Shuu childhood friend, at the second chapter nina thinks they gonna get married because she read that in a manga.

He usually appears fairly regularly although he remains a support character

It's Seems both Shuu and Tomoe have a romantic interest in each other, but they vigorously deny it while everyone around them (even nina) expect them to get married, but something does seem to be developing between the two.