Chapter 187 (Online)

"The Butterfly and the Back" (蝶と背中, Chō to Senaka, Tonari: 232) is the 187th chapter of the One-Punch Man manga series.

Short Summary
It is revealed that the Hero Association had been running a "hero gambling" system. To make more money some situations are rigged. The hero Mad Devil Yankee is forced into playing the part of a very weak hero and sent to defeat Shiverhuahua. The plan backfires when the monster is much stronger than imagined. Before Mad Devil Yankee goes down, Saitama obliterates the monster, seeing his odds, Saitama becomes angry and decides to bet on himself, but it doesn't work out.