Have to wait over a month before getting my last paycheck

Long story short, I finished my contract in mid-March. My employer usually pays the entire month’s salary at the end of the succeeding month. So, I’m still waiting for February’s paycheck, almost two weeks after finishing my contract.

Now, I’m leaving Japan in April, and won’t be around to receive my last (half-month’s) paycheck. I’ve already returned my shakai hoken card and everything. My (previous) employer wants to remit my paycheck to my overseas account at the end of April.

Is this allowed? I’ve heard others mention all outstanding wages have to be paid within a week after the end of work.

Thanks!

Edit: spelling