Extra Edition 10 (番外編１０, Bangai-hen 10) is an online-only unnamed bonus chapter of the One-Punch Man manga.
Summary[]
Genos is seen approaching Saitama, who asks him if he had changed his parts once more. Genos answers with a yes, saying that it was Dr. Kuseno who has upgraded him, and that his strength and speed have been enhanced further. Saitama then notices and asks Genos if he got a haircut, which the cyborg acknowledges, stating that his hair is now made of heat and shock proof fiber. Saitama seemingly expresses his surprise, with Genos loudly saying that he will ask Dr. Kuseno to transplant hair for Saitama, as well. Saitama, apparently, becomes angry towards Genos as he says he did not ask him for that.