Saitama is your sensei, you have time travel powers. So of course you asked him what did he look like when he had hair, he didn’t have any pictures so you had to time travel to see. So you did, you timed travel to the past where Saitama had hair, you were walking around and you think you spotted him. He was just running or jogging somewhat, you walked in front of him and he halted.

“H-huh?, who are you?…you need something?.”

He panted, he tried to catch his breath. He was handsome as hell.