Chapter 25

Sakamoto works out that his blows have been landing on the enemy even when he aims at Shin, and Horiguchi cheerfully explains why. A shot fired into Sakamoto's neck scrambles his brain into swapping friend for foe, so any attack he throws at an ally quietly misfires. The scientist wears an arm-mounted device that lets him flip these signals on demand, and he doses himself to swell with muscle before charging the pair.

The fight becomes a puzzle of reversed intentions. When Shin lunges to kick, Horiguchi trips the switch so the blow lands on Sakamoto instead, then juices his own leg for speed and strikes Shin down. He boasts that the mind pulls its punches the instant it believes it is hitting a partner, and that even a legend like Sakamoto is undone by pure science. He mocks Shin's mind reading as a useless gift, since knowing a thought means nothing if you cannot command the body, and he sneers at the chief for valuing something so worthless.

That insult lights the fuse. Sakamoto vows to prove the telepathy is no joke, then feeds Shin a plan without speaking a word. He begins hammering every possible target at once, so a strike connects no matter which way Horiguchi flips the signal, while Shin leans on his clairvoyance to slip Sakamoto's own swings. Together they flatten the scientist. Freed of their electrodes, the lab staff thank Shin despite how they once treated him, and he shrugs it off, content with his abilities and his new life.

Horiguchi reveals that the neck injection inverts Sakamoto's sense of ally and enemy, and that his arm device can toggle the effect mid-fight. Sakamoto counters by attacking all targets simultaneously so a hit registers regardless of the switch, while Shin uses clairvoyance to dodge Sakamoto and read Horiguchi. The two defeat the scientist in tandem, and the lab crew removes the electrodes.

The chapter carries the Japanese title Saiensu Yarō, rendered as Science Bastard, and spans nineteen pages. It debuted on May 31, 2021 in the 26, 2021 issue and closes the Lab Arc thread in Volume 3. The cover features Sakamoto, Shin, and Mad Horiguchi; Namiki also appears. A running gag books the ending, as Sakamoto silently pictures stabbing Shin over a jab about his weight.