After rigorously training for three years, the ordinary Saitama has gained immense strength which allows him to take out anyone and anything with just one punch. He decides to put his new skill to good use by becoming a hero. However, he quickly becomes bored with easily defeating monsters, and wants someone to give him a challenge to bring back the spark of being a hero. Upon bearing witness to Saitama's amazing power, Genos, a cyborg, is determined to become Saitama's apprentice. During this