I am in need of mangas where the main character, normal, seemingly average person, is acquainted with some of the most powerful and important people. Everyone's else is intimidated by these high-ranking figures, then main character goes "Oh, hey [character name]", completely nonchalant.

I guess a similar story I can think of at the moment are One Punch Man, with Saitama and Class S Heroes. But whatever genre is fine.

I am bored and please suggest manga or whatever similar threads like this. 😁

Beelzebub
F. Compo
Joshikousei Kagishi Saki
Komi-san wa Komyushou Desu.
Uchi no Musume ni Te o Dasu na! - Oyako Heroine Funtousu

First ones to come to mind, though some are stretching it as far as the MC's status and what you're looking for.

________________