One-Punch Man Manga Volume 20 features story by ONE and art by Yusuke Murata.

Immediately before the big Monster Association battle, the Class-S heroes hold a strategy meeting. Unfortunately, they just aren’t in sync, and when Amai Mask barges in, the situation only gets worse. Thankfully, King appears just in time to boost their morale—and it’s a good thing, too, because the big monster battle begins!