difficult 5th grade classes

I'm looking for some advice and suggestions for my 5th graders. I was a long term sub at this elementary school for a few months this year and was just asked to return for the remainder of the school year (about 5 weeks). at this school I have 2 5th grade classes and I see each of them 2x a week for 30 minutes.

both of them are extremely difficult classes for myself, their usual music teacher, their classroom teachers, admin, pretty much everyone on earth. they don't listen to instructions, they are incredibly rude to each other so they are prone to fights, and they do not handle tools/equipment/instruments safely or responsibly so it's tough to find an activity or topic that works well for them.

I heard that in the fall they were really into Japanese music and culture so I wouldn't mind doing something with that. when I was there I got most of them to come up with some soundscapes as a group using hand percussion which went alright, I tried having them do bucket drumming later but there were several bucket casualties so bigger instruments are out of the question for now. we have access to quaver and computers, I haven't ever tried that with them but I'm open to it.

if you have ANY ideas or tips or suggestions for what I could do with these classes for the next couple weeks I would seriously appreciate it. I will try just about anything, I just want to be able to do something fun and safe until the year ends