Youko is one of Fumi's friends at Matsuoka Girls' High School.

She, Motegi and Misako appear to be long-time friends giving one another the nicknames Pon-chan, Mogi and Yassan respectively.

She is slightly immature though probably the boldest and bluntest out of the three friends. She is also very unrelenting and dedicated to whatever she believes in. For a very long time, she tries getting Fumi to join the Drama Club despite Fumi's rejection of the club. She is very loud and outspoken though she easily is able to speak to people and get to know them better. It was through her efforts that Fumi even became friends with the trio.

Pon-chan seems to be a little hapless and complains that things never go her way.