Hideo Jojō's 'Confession ~ The Secret of Machiko Matsuoka ~' Matsuura Hiromi is a female teacher living with her sister, Hara Saori, but she had once been caught by her sister in the act of stealing her boyfriend, which led to Hara attempting suicide by jumping off a building, resulting in her permanent inability to walk. Feeling guilty about this, Matsuura was manipulated by her sister's orders. One day, a male student who was running errands for the class came to Matsuura's music room and asked her to teach him piano because he wants to apply to a music university. From then on, Matsuura was returning home late after lying to her sister to teach the student, but one day she was caught renting adult videos by a classmate. This work depicts the complicated relationship of the sisters who have a shared past. When Matsuura returns home, out of resentment for having her boyfriend taken away and Hara's influence leading to her injury, she is ordered around by her sister. At school, she is also a teacher who is not highly regarded, so she finds herself in a situation where her only solace is secretly borrowing adult videos, and she has feelings for the student she teaches piano to.