Misora, who is about to take the university entrance exam, moves to Tokyo to take the exam. She decides to stay in her sister's apartment for a while. Even after getting married, her sister still works and has a hard time paying attention to her husband. Seeing her brother-in-law like that, Misora ​​decides to use him to get revenge for being dumped by her boyfriend. She does whatever she wants, such as giving him a blowjob right next to her while he is sleeping, or trying to have sex with him when she is drunk. Before they know it, the two of them start to get excited about doing naughty things behind their sister's (wife's) eyes...