Is this legal?

[FBFAN]

Here's the scenario. High school ball on a kickoff.

The K team has the kicker setup on the right hash, ball teed up on the 40, in position, waiting for the whistle to blow.

The other 10 players are lined up shoulder to shoulder on 30 yard line adjacent to the left sideline.

The referee blows the whistle and the K team goes for an onside kick from where they were aligned.

Is this legal? Or, do a certain amount of K players need to cross the hash then shift to where they are aligned?

Thanks in advance.