Chapter 150 (Online): Master and Disciple

Garou shifts into the Exploding Heart Release Fist, an old form Bang practiced before creating his Water Stream Rock Smashing Fist. Both Bang and Bomb are startled, and Bomb asks how the youth got hold of a technique Bang had locked away. Bang recalls that Garou once cracked open the dojo's safe and read the secret scrolls inside. Seeing his abandoned style in action stirs memories, but Bang refuses to lose.

A flashback reveals Bang as a violent brawler who hospitalized challengers until Bomb, sickened by the cruelty, confronted him. Bomb warned that raw power had not cured his younger brother's inner turmoil and set out to teach him humility, defeating him and telling him to cool his head. Chastened, Bang built a defensive style and opened his own dojo, which Bomb quietly watched flourish over the years. Back in the present, Bang tells Bomb to keep his eyes on him, vowing to reach Garou through his fists and resolving to give up hero work so he can reclaim the role of the boy's teacher.

Meanwhile, Genos and Tatsumaki are overwhelmed by Black Sperm, who tears off the cyborg's limbs. Tatsumaki tells him to run, but Genos reflects that his old self would have detonated and endangered nearby heroes; instead he protects her with his ruined body. As Black Sperm mocks his crawling, the roar of King's King Engine cuts through.

Garou reveals he learned the Exploding Heart Release Fist by breaking into Bang's dojo safe. A flashback establishes how Bomb humbled the reckless young Bang and inspired him to found his own school. Bang decides to retire from heroics to mentor Garou again. Genos rejects self-destruction, choosing to guard Tatsumaki, moments before King arrives.

The chapter draws partially on Chapter 71 of the webcomic and sits within the Monster Association Arc. Bang and Bomb share the cover. It parallels the print-numbered run, since the online and volume releases are counted separately. It was published on October 9, 2021.