Piltover Country Club 친목질 is a slang that most often refers to a closed gang of oldbies who exclude new comers or less 'active' members.

High Five, Cupcake!

Hey Jayce~ Power Slam!!

When you play the game, you will often find pretty interesting easter eggs for the champions from Piltover.

The new champion, Jinx, also has many

You're gonna chase me? Fat hands! Korean version of this quote is "You wanna fight me? You won't hit anything with fists that clumsy!"

...but there others, like this guy, who don't have any.