The leader of the tennis club, Kaori Kitamura, has recently had a problem with another student, Ami Sasaki, who regularly skips practice. One day, the club manager asks her to go to the problematic student's home to check on her. On the way, her childhood friend Seiya warns her that Ami's been out of control recently. However, being the club leader, Kaori believes that she can convince Ami to return to practice. There's a problem though. With Ami's heart no longer invested in the club, Kaori, once her absolute leader and ace of the club, had in Ami's eyes become nothing more than a regular girl one year older than her, thus Kaori's words aren't able to convince her. On the contrary, she has a cruel idea. She wants to make Kaori fall from her blindingly bright world, into the scummy one that Ami now inhabits. She uses her own fuck buddy to abuse Kaori and carries out her plan. This is the beginning of Kaori's fall.

(Source: Coolmic)

Note:
This has 2 versions. One is the original multi-work doujinshi series of 4 parts with mosaic censorship, later compiled into 1 volume. The other is a fully censored version published in 2023 by BLIC-ERO, split into two parts with two chapters each. The covers are different, but the story is the same.

The official English translation by Coolmic is based on the fully censored BLIC-ERO version and it further splits each part into multiple chapters.