(dub) 6 : The Terrifying City <Essential — BREAKDOWN>

: The Hero Association investigates the "ghost town" area of City Z, which is rumored to be a hotbed for powerful monsters.

: After five days as a professional hero, Saitama learns from Genos that Class C heroes are removed from the registry if they have no heroic activity for a week. (Dub) 6 : The Terrifying City

: While patrolling, Saitama encounters Speed-o'-Sound Sonic , who is desperate for a rematch. Saitama eventually subdues him after Sonic begins terrorizing the town to force a fight. : The Hero Association investigates the "ghost town"

: Reappears as a persistent rival to Saitama. Saitama encounters Speed-o'-Sound Sonic