Chapter 18 (Vigilantes)

Rewinding by a minute, Team Pit O2 reports three minutes left to halt the bus. Ingenium admits he is nearly spent, and the truck backing him is out of commission, so the call goes out for anyone with a mobile Quirk. Koichi volunteers, pulling on the hoodie he picked up at a souvenir stand, and leaves over his mother's objections that the risk is too great. As Shoko begins to faint, Knuckleduster and Kazuho arrive, and Pop☆Step tends to her.

Returning to the present, The Crawler and Ingenium draw level with the bus and weave around the Monster Cat's lashing tails. The plan is for Koichi to draw the creature's attention from the front while Ingenium retrieves Makoto from the rear, but the antenna on Koichi's hoodie sends the cat into a sudden burst of speed. Ingenium spends Recipro Burst for one last surge before his engines force a cooldown to keep from overheating. Told the edge is two hundred meters out, The Crawler insists on going after Makoto alone and dodging the tails himself, over warnings about how dangerous that is.

Koichi boards just as the bus tips off the expressway and falls. Ingenium answers with his ultimate move, Rocket Charge, calling for the boy to leap so he can catch him. Gliding and rocketing up the bus are not enough on their own, so Koichi wills himself into a second jump with nothing beneath his feet. Shoko remembers her son moving in open air before he could even walk, and how she smacked him each time out of worry until he stopped. Knuckleduster observes that every child eventually flies at some point, and the only thing a parent can teach is how to land. Ingenium secures Makoto, both Quirk users touch down on the expressway, and Koichi tumbles to a stop as the bus crashes below and Kuin slips away with the cat.

Shoko decides she trusts the people she has met and announces she is heading home. When Koichi says there is no rush, a slap answers him, since the words are not what he actually means, and she then hands Knuckleduster and Kazuho standing permission to smack him should he misbehave. Makoto gets an invitation into the family as well, and answers that she will give the offer thoughtful consideration. Later, Kazuho measures Koichi's hover at thirty centimeters and suggests practice could stretch it to fifty, enough to clear a curb. Koichi insists the double jump was real despite her belief that he imagined it, though he cannot reproduce it, and credits the power of Asakusa for it.

Koichi joins the pursuit of the hijacked bus and boards it as it plunges from the expressway. He jumps a second time in midair, a feat he proves unable to repeat afterward, and Ingenium catches both him and Makoto. Kuin Hachisuka escapes with the Monster Cat while the bus is destroyed. Shoko Haimawari accepts her son's companions and offers Makoto Tsukauchi a place in the family.

The chapter carries the title Force of Will Acceleration!, or Kiai de Kasoku!, and originally went out simply as Acceleration before the volume release revised it. Written by Hideyuki Furuhashi with art by Betten Court, it runs twenty-one pages, sits in Volume 3 of the Senpai arc, and was published on November 25, 2017. Koichi and Shoko Haimawari appear on the cover, and Episode 9 adapts it.