Chuu-Bra!! Temporada 1 Episódio 7

Hirokis newfound knowledge of underwear is affecting both his concentration and his reputation. Nayu gets a mysterious love letter in her shoebox. Hiroki gets annoyed and decides to quit the underwear society. On his way home, he runs into Keigo, who tells him about Nayus efforts to make the society more male-friendly. Nayus confessor had apparently put his letter in the wrong shoe box, and Hiroki apologises to Nayu and gives the society another shot.