After receiving your provisional licenses, Class 1-A was sent to Nabu Island as part of the Hero Work Recommendation Project to assist the locals. Everyone quickly took up small tasks around the island—everyone except Katsuki, who stayed at the hero office under the guise of "keeping watch," really just flipping through a magazine.

Meanwhile, Mahoro, a local girl, didn’t take the new heroes seriously. She kept making up stories about her younger brother, Katsuma, going missing to waste their time. That night, she and Katsuma staged a fake villain attack using her illusion quirk. Katsuki was furious at having his "precious" time wasted on a false alarm.

But the very next day, real villains arrived. Nine and his crew invaded the island, destroying the ships and terrifying the residents, all while searching for Katsuma. Izuku encountered Nine near the siblings’ destroyed home. Mahoro, panicked, created another illusion—this time of an injured Izuku calling for help.

Katsuki arrived at the scene and, seeing Izuku in danger, rushed in. Together, they fought Nine, but his Hydra attack severely injured Katsuki, breaking some of his ribs. Despite their efforts, both Izuku and Katsuki collapsed from their injuries. Nine was forced to retreat with Slice after overusing his quirks.

Moments later, Ochako, Tsuyu, Shoji, and Koda arrived and rushed the boys to safety, taking them to where the islanders had gathered so the doctors could treat them.