(C65) [Kuroyuki (Kakyouin Chiroru)] Gohoushi Club 4 (Happy Lesson)
[AKIOMI Osuzu] Happy Lesson [ENG]
Happy Lesson [AKIOMI Osuzu] (Vietnamese)
(C61) [Nekoyashiki (Sasaki Mutsumi)] Nekomatagi 4 (Aquarian Age, Happy Lesson, Memories Off, R.O.D)
(C56) [Nekoyashiki (Sasaki Mutsumi)] Nekomatagi (Happy Lesson)
[WHITE ELEPHANT] Oneechan Tamashi (Various) [Digital]
[Keno Yantarou] Tanoshii Kagai Jugyou - Happy Extracurricular Lesson [Chinese]