

In prehistoric times, Primitive Ami and Primitive Yumi create their own music, and Primitive Kaz tries to get the two to join together and form a band.
In their childhood years, Ami and Yumi arrive at Camp Youwannasushi and are met by Atchan, who tells them about Rumaki the bunk monster. Yumi is grabbed by Rumaki and Ami and Atchan go under the bed to save her. They manage to save Yumi, but she does not believe them because she was in the sack for the whole episode.
Yumi needs a new guitar and must accomplish certain tasks to get one. So she meets Master Mei Pie, who sends her to get some items. She collects all the items, but realizes that she was not focusing on her playing.