Gaku, age 12, is another one of Naota's classmates and close friends. In episode three, Marquis de Carabas, he plays the part of a mouse in the school play. Gaku also uses the word "chu" constantly, especially when referring to Haruko. This is a pun in Japanese, because "chu" is the Japanese onomatopoeia for both kissing and the sound a mouse makes. In the English version, "chu" is replaced with "smooch" to make more sense to English speaking audiences. He's somewhat hyper (compared to the bored composure of his friends) and is usually seen with Masashi. He is an encyclopedia of bizarre rumors and legends, many of which are sexual in nature.