Sunao Moriyama

Sunao is a male junior high school student with a very serious attitude and in effect shows little emotion, if at all. He is the one to originally find and name Potemayo, and it is perhaps due to this that Potemayo takes a liking towards Sunao. He does his best to look after Potemayo and make sure she is safe, which means he has to take her to school with him everyday. Sunao's mother passed away when he was younger, and since his father is almost never home, Sunao has become very self-sufficient at a young age.

(Source: Wikipedia)