Mainstay

The Main Story arc is the seventh and ongoing arc of Oshi no Ko. It is set six month after the music video shooting in Miyazaki, and B-Komachi's popularity skyrocketed after said music video became an instant hit.

Summary
Six months passed since the trip to Miyazaki. The careers of Aquamarine Hoshino and Akane Kurokawa moves forward, as they both land acting jobs as supporting characters in a drama and headlining a drama respectively. After their music video became viral, B-Komachi's popularity also began to grow. But internally, members of B-Komachi are distant from each other. Kana Arima is struggling to reconcile the fact that Aqua is actually dating Akane, and even started to deliberately avoid meeting her. Mem-Cho, who noticed Kana's mood one day, managed to dig the truth out of her and confronted Aqua herself. She was, however, met with the fact that Aqua doesn't like avoiding Kana, but has to do it in order for her career to grow, and to avoid another case like her mother, Ai Hoshino.

Meanwhile, Ruby Hoshino has been meeting with the previous president of Strawberry Productions, Ichigo Saitou, and drilled him regarding her and Aqua's father. He refused to divulge the information, but said that he will arrange a meeting with people that might know about the information if she gets popular enough. Ruby followed his advice and got a job as a reporter on the show "Dig Deep! One Chance", coincidentally the show Aqua is also starring. She also became closer with the Assistant Director of the show, Shun Yoshizumi.

As the days gone by, Shun began noticing how often Ruby is approaching him. At one point, Shun is asked to search for cosplayers to feature on the show's segment. He has difficulty finding any cosplayer that can fit the bill, and his distress was not gone unnoticed by Ruby. Shun asks her for help in filling in one of the cosplayer's slot, and she also started asking Minami Kotobuki to join as she has expressed interest in the show before. Meanwhile, Shun asks his younger sister, Mimi Yoshizumi, to fill the slot as she is also a cosplayer alongside her main job as a VTuber.

Chapters

 * Chapter 81: Progress
 * Chapter 82: B-Komachi Nights
 * Chapter 83: Fixation
 * Chapter 84: Pitching an Idea
 * Chapter 85: Calculation
 * Chapter 86: Assistant Director
 * Chapter 87: Lies
 * Chapter 88: Offer
 * Chapter 89: Cosplay
 * Chapter 90:

Characters

 * Aquamarine Hoshino
 * Ruby Hoshino
 * Kana Arima
 * Akane Kurokawa
 * Mem-Cho
 * Miyako Saitou

Introduced

 * Shun Yoshizumi
 * Mimi Yoshizumi