Apricot summer who came to Tokyo for the university entrance exam and stayed at the house of his brother and his wife. Anzu, who is sullen and perverted, has few same-sex friends. Hikaru, my sister-in-law, has a friendly personality and speaks without hesitation. Anka is gradually drawn to Hikaru. While her brother is on a business trip, Hikaru ignites Kyoka's eroticism and tries to make her her own sex slave. Anka is gradually drawn into the world of perversion.