One-Punch

One-Punch (ファイト一発) is the 245th chapter of the manga it is also the first and only chapter of the One-Punch Armor Arc.

Synopsis
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.

Plot Overview
Gosunkugi is surrounded by a group of three street thugs, all of whom are wearing masks. The thugs say that if Gosunkugi hands all his money over they won't hurt him... much. Gosunkugi decides that he better introduce himself, as he does so he goes and gets a nail and hammer out of his satchel. At first he seems willing to hand them over, but Gosunkugi actually attempts to hit one of the thugs with them. However, the thug manages to avoid the nail and the group decide to start beating up Gosunkugi.

Shortly after the thugs begin beating up Gosunkugi, Ranma arrives and defeats the thugs with ease. Ranma then notices that it was Gosunkugi who was getting beaten up. After Ranma asks if he's alright to which Gosunkugi replies he's fine and thanks Ranma for his help.

Akane then appears and asks Ranma is he's trying to pick another fight. Ranma replies that he was just helping Gosunkugi since he was in trouble. Akane then asks Gosunkugi if he's not hurt. Seeing Akane's concern delights Gosunkugi and he says that he's sorry for her to see him like this. Ranma then tells Gosunkugi that it's fine since Martial Artists have to protect the weak and downtrodden. Ranma and Akane then leave.

As Gosunkugi watches them leave he becomes very angry at Ranma's belittling of him in front of Akane. Gosunkugi then begins talking to himself how much he despises Ranma, but Gosunkugi continues saying that Ranma isn't all bad since he saved him. He then begins to walk off, continuing to say that he can't talk to Akane since he knows Ranma will belittle him. He then wishes there was a way for him to become just as strong as Ranma, if not even stronger than him.

Gosunkugi is in his room, reading a magazine. He then comes an advertisement for the One-Punch Armor, where a man named Jack Seiler talks about how buying the armor has allowed him to get all the women he ever wanted, as well as making him able to defeat all his enemies. Needless to say Gosunkugi orders one of the suits. When the suit arrives Gosunkugi tries it on and then begins to fantasise about him defeating Ranma and Akane finally falling for him. However, Gosunkugi is unable to stand up while wearing the suit because of how heavy it is.

Ranma receives a letter from Gosunkugi (who hasn't be seen at School for the past three days), challenging him to a duel; the letter also tells Ranma to pick up Gosunkugi from his house. Ranma does as the letter asks and goes to Gosunkugi's house. When he arrives, Ranma sees Gosunkugi with his parents having some tea. Gosunkugi explains to Ranma that he couldn't move because of the suit so he had to bring Ranma to him. When Ranma asks why Gosunkugi didn't just take the suit off he explains that he couldn't since it has an automatic lock for safety reasons.

Gosunkugi continues to explain to Ranma that if he doesn't punch his strongest opponent once the lock stays on and he can't remove the suit. Ranma then hits Gosunkugi in the back of the head and says that's a though break, Ranma then continues to ask Gosunkugi is this means he's his strongest rival. Gosunkugi replies yes and tells Ranma he's as quick as ever. Gosunkugi then releases a chain from the arm of the suit and is able to stand up finally, much to delight of his parents. Once he stands up, Gosunkugi punches table in front of him, this leads Gosunkugi to deduce that the suit waits for the enemy to come into range; it then latches onto them and powers up. As he says this Gosunkugi's parents are glad their son finally grew a backbone and is now practicing martial arts.

The suit then prepares to punch Ranma again, as Gosunkugi asks Ranma to let him punch him just once so he can get rid of the suit. Ranma says there's noway he'd allow that and tells Gosunkugi to give it his best shot. Gosunkugi then swings at Ranma, but it just manages to dodge it, causing the wall behind him to be hit instead and crumble. Gosunkugi then comments of the power of the suit and how incredible it is, he then realises with this he can finally defeat Ranma and runs off to Furinkan High School (dragging the still chained Ranma with him).

Gosunkugi and Ranma prepare to begin their fight, while a large number of students gather around them. Ranma then asks Gosunkugi if it isn't enough for him to defeat him, but he has to do it front of the student body as well. Gosunkugi explains to Ranma that just facing him in a fight is thrilling and that beating Ranma to a bloody mess is just a bonus. Akane then runs towards the fight, shouting to Ranma that him facing Gosunkugi is like kicking a puppy, but she quickly stops when she sees Gosunkugi spinning Ranma in the air by the chain to the suits arm. Gosunkugi then throws Ranma to the ground. Hiroshi and Daisuke (who had come to watch the fight) say that this is surreal, while Akane wonders what in the world is going on.

Having seen Akane, Gosunkugi tries even harder to defeat Ranma, but after throwing a punch which misses Ranma sees his chance and manages to kick Gosunkugi. Continuing the onslaught, Ranma hits Gosunkugi with several punches to the chest. However, Gosunkugi simply stands up afterwards saying to Ranma that his punches won't do anything to him so long as he wears the suit.

Ranma begins to worry as to how he's going to win. Just then the suit begins to beep and a countdown begins on the front of the suit. At first Ranma and Gosunkugi wonder what the countdown is for, but then the suit says that the battery will fail in five minutes. Hearing this Ranma decides to have another stab at fighting Gosunkugi. Daisuke asks if this means that if Gosunkugi can't punch Ranma in five minutes Ranma wins. Gosunkugi replies, while trying to punch Ranma, that it isn't quite like that and the suit will explode if he doesn't manage to hit Ranma. A number of students then run away in horror.

Gosunkugi goes in for a punch but misses again. Hiroshi and Daisuke try and convince Ranma to let Gosunkugi punch him, but Ranma refuses. Akane then joins in and angrily tells Ranma to just let Gosunkugi punch him. Ranma replies, equally as angrily, that this is a fight between honourable men and that Gosunkugi won't be satisfied with a hollow victory. Gosunkugi is touched that Ranma has respect for him, but the countdown is down to 10 seconds and he doesn't want to explode. Gosunkugi then tries for one last punch at Ranma, but Ranma stops the punch from connecting so the suit explodes. Gosunkugi then falls over as Ranma declares his victory. Meanwhile, Akane calls Ranma an idiot and Gosunkugi lies on the ground saying once he feels his body again he'll congratulate him. Daisuke just calls Gosunkugi and Ranma a pair of idiots.

Cast in Order of Appearance

 * Hikaru Gosunkugi
 * Ranma Saotome (male)
 * Akane Tendo
 * Gosunkugi's Parents (debut)
 * Hiroshi and Daisuke

Quotes

 * Actually... I'm thrilled that I'm here TRYING to right you instead of cowering at home. But beating you into a bloody mess will be a nice bonus! - Gosunkugi's response to Ranma after he mentions it's not enough for him (Gosunkugi) to defeat him, he has to do it in front of a crowd.
 * Ranma... you're a moron. - Akane talking to Ranma after the fight.
 * What a pair of idiots. - Hiroshi's comment about Ranma and Gosunkugi.

Trivia

 * The opening scene with Gosunkugi being threatened by the three thugs was incorporated into the OVA Stormy Weather Comes to School! Growing Up With Miss Hinako.
 * In the OVA, however, Hinako Ninomiya saves Gosunkugi, not Ranma.
 * The One Punch Suit is a reference of Fire, main hero of the Metal Hero Tokusatsu Series Tokkei Winspector.