Muroi Ayumu is Yuri's little brother.
Ayumu has short light hair.
Ayumu works really hard for little things. He wishes that people would stop going to him for everything.
When he was little, his mother died.
- "Excuse me for being merely average and not rising to the occasion." Ayumu says this to Hikaru after he says that he thinks too hard about little things. (Volume 2)