The sweltering heat continues day after day. It is summer. Mother Rie and her son Yoshimune. One day, both mother and son are fed up with the heat. When Yoshimune, unable to bear the heat, takes off all his underwear, his mother also takes off her clothes and bra and tries on a camisole. Realizing that this outfit is surprisingly comfortable, she starts spending her days without a bra. However, for Yoshimune, who is of an age, this is too stimulating...