Chapter 21

 is the twenty-first chapter of the OnePunch-Man manga series.

Part 1
Genos reads out the news that Saitama went from last to the 342th place. Saitama is not impressed by it, and asks what Genos has been doing. Genos explains that he ranked 17th, but 6th in popular votes, much to Saitama's shock. Genos reads, without embarrassment, some commentaries of others about him that wrote their impressions after looking at one picture of him. Despite that, Genos exclaims that he has yet to meet someone as astounding as his teacher, to which Saitama is creeped about it.

While they are talking, miles above them near Earth, a giant meteor is on impact route to the planet. Genos is called to go the Heroes Association for some unknown reason. Genos arrives at the Z-City Branch, with a suitcase, where he meets Bang. Genos recognizes Bang as the 3rd ranked S-Class Superhero. Bang explains that everyone from the Heroes Association evacuated, as all S-Class heroes were called to go there, and they are the only two remaining. Genos wonders why, which Bang continues to explain that everyone is preoccupied or didn't bother, since they were ordered by the Heroes Association for an unreasonable Dragon level disaster task. Bang was ordered to stop the impact of the meteor, which could wipe out Z-City, and by protecting the people from the meteor will make the Heroes Association's name rise.

However Bang claims it impossible, and advices Genos to evacuate. Genos still stays and asks if the citizens were informed. Bang explains that half a hour ago, they that tried to estimate the point of impact and will announce an evacution notice. Despite all that, Bang shows a fearless expression of the coming panic. The alaram signals, and Genos wonders what Bang is going to do. Bang is going to stay and is going to protect his dojo with his Rock-Smashing Water Streaming Fist. Aas he turns around, he notices Genos already left the building. Above them, The meteor destroys a satellite near orbit, heading closer to the Earth.

Part 2
The warning signal to evacuate louds, shocking the citizens and are left without hope. Genos leaps from rooftoops and notes that the meteor will also destroy the outskirts of Z-City. He decides to test his prototype, and activates his suitcase which shows the words "Arms Mode". He throws the suitcase in the air, which forms into a set pair of arms and attaches it to his arms and lands on a rooftop nearby the point of impact. Genos wonders if he can do some damage with his incineration cannons and hopes to protect his teacher. As he prepares himself, a huge robot flies above him towards the point of impact of the meteor.

Part 3
The mechanical robot flies towards a building and lands on it. Genos approaches the robot and wonders if it is "Bofoy".

Characters in order of appearance

 * 1) Genos
 * 2) Saitama
 * 3) Bang
 * 4) Bofoy

Chapter notes

 * This chapter is the start of the Giant Meteor Arc.