Surprised after watching the Little League World Series Korean team play

It's Little League, but they haven't made a single error in two games.
Furthermore, they are pulling off plays that would be difficult even for adults.
They hit home runs in both games, gave up zero runs,
and although they allowed four hits across both games, they were in a no-hitter situation for a long time in both.
It seems like there are almost no walks either. I don't remember anything other than walking the first batter of the second game.
They have pitchers with great control, which is rare even in adult teams.

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In the broadcast of the second game, it mentioned that the Korean team scored 70 runs and allowed only 1 run in 7 games, so there must have been preliminary rounds before this.