One-Punch (ファイト一発 Faito Ippatsu?) is the 245th chapter of the manga it is also the first and only chapter of the One-Punch Armor Arc. Gosunkugi gets cornered in a vacant lot by some hoodlums and after trying to fight back, gets beaten severely. Ranma arrives and saves the day, but Gosunkugi is embarrassed when he realises Akane saw it all. Gosunkugi heads back home and sees an ad for a strange suit in the back of a manga magazine. He orders the One-Punch suit and then sends out a challenge to Ranma.