S1·E41 There's No Business Like Shogi Business

Shōta Taniyama loves the game shogi and is able to defeat the vice-principal, but his parents are against his desire to play. With the help of Miss Seki, they allow him to play in an upcoming tournament. Taniyama makes it to the final round but becomes nervous whenever he touches a certain piece. Doremi, Hazuki, and Aiko use this clue to identify the presence of a Bad Card.