Meaning of “Mob(モブ)” / “MobChara(モブキャラ)”

“Mob(モブ)” means “one of many others” or “person without any character” as a Japanese slang.
“Mob(モブ)” is an abbreviation for “MobChara(モブキャラ)”, and Chara(キャラ) is an abbreviation for character.
“Mob(モブ)” is from English mob, but the meaning is different.

You can find this slang in Manga or Anime.
For example, have you ever seen like this story?
“One day, a mob(モブ) boy (not attractive, without any character, low-key) suddenly get super power”.
“One day, a mob(モブ) guy reincarnate in a different world”
“One day, a mob(モブ) boy meet a strange girl.”
Kind of…
Anyway, “Mob(モブ)” is a really common slang.

Example Conversation

A: Ah… I’d like to ask Yui-chan out…
B: Why not?
A: I’m mob(モブ), so it may be that she doesn’t know me.
B: She know, you are a classmate.
A: I don’t have the courage to do it, I’m Inkya and mob(モブ)!

A: あー、ゆいちゃんとデートしたい・・・。
B: 誘えばいいじゃん
A: いやぁ・・・俺モブだから、ゆいちゃんに認識されてない可能性もあるし無理。
B: クラスメイトだから、さすがに知ってるでしょー
A: 陰キャモブの俺にはそんな勇気ない。