Six pieces of theme music by the J-pop group Buono! are used for the first season—two opening themes and four closing themes. The opening theme for the first twenty-six episodes is "Egg of the Heart" (こころのたまご); and the last twenty-five episodes, "I Love Everyone" (みんなだいすき). The closing theme for the first twelve episodes is "True Self" (ホントのじぶん); episodes thirteen to twenty-six, "Love Rider" (恋愛ライダー); episodes twenty-seven to thirty-nine, "Kiss! Kiss! Kiss!"; and the last twelve episodes, "Do Your Best and Go!" (ガチンコでいこう!).