Rinji Kanrinin-san

"A Hero of Justice is the Hero of Justice, things that they can do, are things that they must do."

A muscular man wearing a mask which makes him look like a professional wrestler. His real name is unknown and he is only known as "Kanrinin-san" or "Mask Man-san".

Surprisingly, he gives advice to Hayato, becoming a dependable adult, but has a tendency to avoid contact with the other residents (the girls) other than Hayato as much as possible.

It seems that he is hired because the boarding house is already old, and the management (including repairs) could not be handled by Momoyo alone, however, not even the old resident like Mikuri is informed of the details.

His professional wrestler physique does not seem to be for show only and his strength is the same as or even more powerful than Marron Branche.