The manga Oshi no Ko by Aka Akasaka ( Kaguya-sama ) and Mengo Yokoyari already has 1.5 million copies in circulation. According to information , the numbers are given with only 4 volumes published.
Synopsis:
The story follows a 16-year-old doctor and “Idol” fan named Ai Hoshino , one fine day Hoshino shows up at his office, saying she is pregnant with twins, and her manager tells her to abort the babies. But Idol doesn't want to have an abortion, she wants to have both children. Afterwards, the doctor is attacked and killed, reincarnating as one of the Idol children .
Finally, the manga is released by publisher Shueisha.
Via: Yorimen