Kojin Jugyou

Aya discovers sex with her love, who now happens to work at her school. The romance slowly escalates.
A mermaid and a knight of Kuonji who inherited the trace of a large company due to the sudden death of their parents. Mermaids sell their bodies to secure loans and aid to maintain the company. The knight, who has surpassed the limits of his sister who devote himself to a man one day after another, asks the mermaid to kill him. However, the mermaid rebukes such a knight for the same sadness that he had lost his parents, and apologizes that he will die if the knight dies. The knight recovers from the words of her sister, who should have had a harder time than herself.