Chapter 6 (Team-Up Missions)

A boat carries Mashirao Ojiro and Toru Hagakure toward Oku Island. Toru asks the only other passenger whether he is a tourist; he confirms it and asks after them. Mashirao explains they are hero students booked to present at the island's hero elementary school, and the man wishes them luck before moving off.

A rope stretched across the road outside Terakoya School catches Mashirao's eye. Clearing it so nobody trips springs the trap, and a net takes him. Toru finds it hilarious and denies any involvement. The culprit is Ikkaku, a boy with a horn growing from his head, who laughs at the catch and bills himself as a hero in the making. The school's teacher cuts Mashirao loose and apologizes, noting the boy pranks everyone, then explains that the visitors come from U.A. High School, which delights him.

Mashirao introduces himself as Tailman and invites questions. Ikkaku wants the Quirk; the room shouts guesses about laser beams, explosions, super speed. The answer, Tail, deflates them. Asked what becoming a hero takes, he says daily training and studying, and Ikkaku labels him super plain, holding forth on how heroes are supposed to be cool and strong with impressive powers. Toru then unleashes Warp Refraction, her Ultimate Move, and the room lights up. She gives her name as Invisible Girl and her Quirk as Invisibility. Ikkaku tells her about legendary ruins on the island hiding a treasure that would win the finder everyone's respect, and asks her onto the awesome team he plans to build. She points out that Tailman comes with her; Ikkaku refuses on grounds of plainness, which lands hard.

The kids head home. Ikkaku shows off on a fence despite his classmates' warnings, senses something with his horn, jumps into a ditch, and lands inside the secret ruins. Mashirao is having tea with the teacher and stewing over the reception when the other children run in: Ikkaku went in alone and has not come out. The two students go after him.

Inside, the traps come constantly, and only Mashirao sets them off, since invisibility leaves Toru undetected. She cheers him on, at one point offering a kiss if he makes it out, which he misses entirely, so she covers by claiming she only said he could do it. Then he doubles back toward the temple's front, leaving her behind. Ikkaku, stuck where his Quirk cannot take him any further, assumes Mashirao came for the treasure and is told otherwise: he came for the boy, having reasoned the traps would stop him early. Ikkaku snaps that he never asked for help. Mashirao says he understands the reckless stunts, because the boy is ashamed of a modest Quirk, and Ikkaku nearly cries admitting it, since a Horn that occasionally senses things looks weak and useless beside his classmates' powers.

The comforting breaks off when Toru comes running and the floor starts giving way. Behind it is the boat passenger, who came hunting the treasure, found only traps, and decided to level the place. Any stone he touches disintegrates. Mashirao grabs Ikkaku clear as the ground fragments. The man threatens to cave the temple in on them, then bolts for the treasure, crumbling the hallway as he runs. With pursuit impossible through the collapse, Toru blinds him with Warp Refraction long enough for Mashirao's tail to put him down mid-boast, and Ikkaku is struck by how strong he is with the Quirk he has.

Back at Terakoya School, Ikkaku brags about finding the ruins and gets scolded for showing off, then allows that his Quirk might have some use worth looking for, since a hero is still what he means to become. Toru points out that Mashirao stands shoulder to shoulder with classmates who have far flashier powers, which makes him plain awesome. As rain starts, Mashirao agrees his Quirk is plain and says he is content being ordinary like most of the world, because it keeps his view grounded, and that is exactly why he is proud of it. Toru appears to kiss his cheek, leaving him red and flustered, then pulls on a glove and laughs that it was only a finger. The rain stops, sunlight picks out part of her smile, and she and Ikkaku both tell him he is awesome.

Mashirao and Toru present at Terakoya School on Oku Island, where the prank-loving Ikkaku dismisses Tailman's Tail Quirk as plain while marveling at Toru's Warp Refraction.

Ikkaku falls into the island's legendary ruins and the two U.A. students go in after him, working through traps that only Mashirao triggers. The tourist from the boat turns out to be a villain who disintegrates stone on contact, and Mashirao knocks him out after Toru blinds him, which finally sells Ikkaku on a modest Quirk.

Thirty-one pages, published August 6, 2020 in the September 2020 issue of Saikyo Jump and collected in volume two of My Hero Academia: Team-Up Missions, the spin-off Yoco Akiyama writes and draws. Toru Hagakure and Mashirao Ojiro share the cover.

Ikkaku debuts here. All Might, Izuku Midoriya, Shoto Todoroki, and Katsuki Bakugo appear only in fantasy panels. Chapter 5 precedes it and Chapter 7 follows.