You're a 1000% right.
Hell yeah. He is all of us
It's King from one punch man
Also love the kinship he has with Rimuru, like how he literally exhibits the same thoughts with Rimuru early on before Rimuru realized he's OP. Like when they were in the Dwarven kingdom where Rimuru thought he was gonna die from the human bullies' attack.
Hence why Rimuru is so sympathetic of him because mah mans already been there done that--
Tbh, Masayuki is kind of relatable. As much as I would like to be like Hinata or Rimuru if I got isekai-ed, I'd probably be freaking out 99% of the time and relying on whatever luck and charm I had to not die. The 'chosen one' skill would honestly be the best option for most of us