Mitsuko finds herself attacked by a Skill-Out gang called Big Spider, but is saved by a red-haired man with a spider tattoo, the description of whom Mii seems to recognize. This incident is shown to be the latest in a string of indiscriminating attacks on espers by Big Spider, which is being led by someone calling himself Wataru Kurozuma. Whilst investigating the gang's home turf in Academy City's 10th District, Mikoto and Kuroko are confronted by thugs who then get beaten by the red-haired man, who becomes their guide to the district having previously lived there. Mikoto and Kuroko head to the Big Spider's hideout, but run into trouble when the gang use a sound system device called "Capacity Down" that affects their esper abilities. The device is disabled by the red-haired man from before, who recognizes Big Spider's leader as Hebitani, revealing himself to be the real Wataru Kurozuma. After he single-handedly defeats the gang, Kurozuma is approached by Mii, and their familiarity surprises Mikoto and Kuroko.