How to earn money as foreigner

Hello guys, I wanted to ask about part-time jobs or ways to earn money in Japan. Currently, I work at a restaurant and earn around 250 000yen . The pay is good, but I’m at university now, and working after classes is quite difficult. I want to have some rest, but keeping up this work pace is a bit hard. I would like to know if there are any not-so-demanding jobs available.
Any tips or personal experiences would be really helpful—thanks in advance!

by AMFsenpai