Chapter 157

Megumi brings his clash with Kirara to a close, but before he can ask for help, the Yuji versus Hakari fight peaks. Wanting only to secure Hakari's cooperation, Yuji quits fighting back and resolves to stay standing no matter how badly he is beaten. To win the sorcerer over, he must show he carries the fever Hakari demands.

Megumi dispels Divine Dog and frees Kirara, explaining he gambled that whichever side had the higher cursed energy output would do the attracting; once he reinforced himself, the pull reversed in his favor. He prostrates himself and begs to be heard, and Kirara, won over, agrees, only for the monitor room door to blow off its hinges with Yuji crashing through it. Hakari storms out in a foul mood and drives a brutal punch into Yuji's face. The first-year refuses to dodge or retaliate, blowing the blood from his nose and declaring he will not fight back until Hakari relents.

Yuji's refusal to defend himself convinces Hakari he is no spy, so Hakari agrees to listen if Yuji can stay on his feet. Asked why he sought him out specifically, Yuji says all his seniors confirmed Hakari's strength, earning another reinforced blow that feels to him like being struck with a serrated bat, Gojo having once described Hakari's cursed energy as having an edge. Hakari insists that sorcerers asking favors are effectively asking each other to risk their lives, and demands Yuji prove his fever. Yuji answers that he has no fever and is merely a cog, a part in the machine that exterminates curses, then turns the question back: what is Hakari's function?

Hakari finds the answer dull and unleashes his hardest strike yet, slamming Yuji into a wall, but Yuji reappears behind him unbroken after three unguarded hits. Looking Hakari in the eye, Yuji repeats that his function is removing curses, that he needs Hakari for that, and that he will not stop until Hakari agrees. Kirara steps in to ask whether Yuji's fever is finally hot enough, and Hakari, acknowledging the fever never lies, agrees to cut a deal. A bewildered Megumi learns from Kirara that, despite still hating the higher-ups, Kirara recalled Hakari's fever burning hottest when he helped people at Jujutsu High.

This Volume 18 chapter concludes the Yuji versus Kinji Hakari fight and is adapted in anime Episode 53. The exchange recontextualizes the chapter title, "Cog," as Yuji's self-definition and crystallizes the fever motif that Hakari has used to test him throughout the Gachinko Fight Club arc.