The entire episode is about Nene and Kaya’s friendship and how it’s their anniversary about something. At multiple points throughout does Kaya cling to and flirt with Nene.
Later, Nene explains to the group that Kaya has multiple anniversaries with her about random things that have happened between them, both in reality and in her dreams.
Continued from the last scene, Eri and Takamine go to a karaoke place together.
Takamine then proceeds to undress and have Eri grope and 69 her.
To explain why Takamine is doing all of these things to Eri: Takamine is unsure about how the MC feels about her and how a lot of her advances have gone nowhere. She then does everything she’s done to the MC on Eri, so she can get the full picture. So this is supposed to be a demonstration, not Takamine trying to seduce or have sex with Eri.
The entire time however, in Eri’s thoughts, she keeps wanting to go further and do erotic things like lick her breasts and have sex with her.
Eri then screams about how hard it was for her to resist temptations and that there’s no way the MC didn’t feel the same way.
At the end of the chapter, Eri’s girlfriend found out about the whole thing and proceeds to punish her.
The chapter starts with a brief time skip from the scene in Ch. 2 Part 3, with Mio waking up to being cradled by Zest’s breasts and their leg entwined.
Mio then recounts how after the scene in Part 3 ended, they all continued to pleasure each other until everyone passed out off-screen.