Yes, this is very late. I keep over-scheduling myself. I have only myself to blame.
One-Punch Man Volume Three collects Punches (issues) 16 through 20 (plus some bonus material) of ONE and Yusuke Murata’s ongoing manga.
Saitama is super-fast, super-strong, and super-invulnerable. He is also super-obscure because neither Saitama nor Saitama’s acolyte Genos have ever bothered to register with the Hero Association. Time to fix that.