One day I wake up in one punch man world

All the characters are not mine except some and MC. English is not even my third language so if there is mistakes, I apologize from the start. Gin (MC) dropped into One punch man world out of blue and the first sight he saw when he opened his eyes was the shrimp monster which is screaming "My name is the Keito. I become a shrimp monster because I ate ten thousand of shrimps in one go.