Mr. Koizumi is the coach of the Katase High table tennis club. He recognises Smile's gift and ability towards the sport and so vows to train him. When Mr. Koizumi was younger he was considered to be the best table tennis player in Japan, and was nicknamed 'Butterfly Joe' because of his extraordinary skills. Mr. Koizumi states that Smile reminds him of his younger self.
Obaba is an old chainsmoking woman who acts as Peco's mentor. She also owns the local table tennis dojo of which Peco and Smile are frequent visitors.
Peco is a member of the Katase High table tennis club, along with his best friend Smile. Unlike his friend, Peco is very charismatic and has a real passion toward ping pong. Peco dreams of becoming the ping pong world champion and claims that he'll move to Europe to start playing professionally after he graduates.
Voiced by 劉�. She has a silent appearance in episode 5. Her speaking debut is in episode 6.