11화: 마코토가 할아버지의 피아노 비밀의 열쇠를 쥐고 있다

11

According to the will of Mr. Kusakabe's former teacher, his granddaughter, Makoto, is the only one who knows the whereabouts of the key to his beloved piano. Can they figure out the secret of the key's location? (Source: Funimation)