Chapter 2

Big Brother & Little Sister (兄と妹) is the second chapter of the Oshi no Ko manga series. It is written by Aka Akasaka and illustrated by Mengo Yokoyari. It was released in Weekly Young Jump on April 30, 2020, and in Mangaplus on April 20, 2022.

Flashforward
A young woman, assumed to be Ruby, is interviewed about her first time working as an actress.

Summary
His dying wish fulfilled, what would the newly reincarnated Gorou do?

Gorou woke up as a baby, one of Hoshino Ai's twin children that she named Aquamarine Hoshino. He still have all memories of his previous life as a doctor intact. He pondered over his circumstances, but decided to live his life as a newborn, cherishing the situation as he was doted on by his new mother and also idol Ai.

Meanwhile, Hoshino Ai returns to her life as an idol, and made arrangement with her company's president Ichigo Saitou and his wife Miyako Saitou. They will take care of the twins while she continued being an idol. Ichigo also reminded Ai to not let anyone knows about her children or it'll be the end for her career and also his own.

After watching and cheering on Ai's comeback on television, it was revealed that his twin sister, Ruby Hoshino, is also someone who was reincarnated.

Characters

 * Aquamarine Hoshino
 * Ruby Hoshino
 * Ai Hoshino
 * Ichigo Saitou
 * Miyako Saitou