[Advice] My JTE tried to attack another teacher at a nomikai

Throwaway account for obvious reasons.

I really need some advice. This post will contain descriptions of violence and abuse so feel free to scroll away if it's sensitive for you. TLDR at the end.

I (26 F) was invited to a nomikai by my JTE (40s M) for this Friday (yesterday). This JTE teaches the 2nd grade at my base school JHS. I get on very well with him, and I generally enjoy his lessons, and I would appreciate that he would include me in things happening in the school like the kids' sports tournaments and the nomikais with his grade. However, I have noticed that whilst he seems to care a lot about the students, he can get pretty scary when he's angry. There have been two instances where it was particularly bad. One time, a boy muttered that he was sleepy during the class greeting, and the JTE stopped the class, berating him in front of everyone saying "well go and nap then! we'll all watch you, so go and take a nap. you said you are sleepy so go to sleep. you (omae) clearly don't care, so go to sleep. go on! go on! sit at your desk, put your head down and sleep!" He then took the boy into the empty classroom opposite and was *screaming* into his face for about 15 minutes whilst the other students were in the classroom with me doing vocab practise. The second time, he yelled at a girl in front of the class because she made a group of three with her friends instead of a pair like she was supposed to. He again was berating her for over 10 minutes and calling her omae.

During these instances, I was at a complete loss on what to do. I did check on the kids after class and they said they were fine and just a bit shaken up. I did speak to my third grade JTE (my advisor) as well, who said that he knew about the shouting because he could *hear it* from his class.... at the other side of the school.

Fast forward to last night at the nomikai. There were about 20 of us in an izakaya that had been rented out by my JTE. My JTE organised the event and invited a couple of teachers from other grades, as well as from the local elementary school. We had a really good night, and it was genuinely very fun, until it wasn't.

One of the teachers, (F 23) realised it was just past eleven o'clock and that it was past closing time. She was so smiley and said "Oh oops! We didn't keep track of the time haha, we need to leave don't we?" to the teacher sitting next to her (M 33 - let's call him Saito). Saito (who is a third grade teacher) then turned to my JTE (again, everyone is smiley and happy and the atmosphere is good) and he says that it's past eleven. The JTE looks at him, stands up and says "What the fuck did you just say to me?!" (今何つってんだよお前?!) And at first, everyone was kind of stunned, maybe thought the JTE was joking, but then he carries on saying "What the fuck did you just say?" and then he leans over the table to grab him (mind you, his elbow is hovering over my head close to my face).

Two teachers immediately hold him back, whilst another teacher tells Saito to go outside. Saito leaves and my JTE starts screaming after him saying "get the fuck back here!" and is screaming his name repeatedly and has completely lost it, trying to go after him and attack him. Saito did literally nothing wrong, was not rude, didn't say anything bad, or anything. We grab Saito's things for him from inside the izakaya and a few teachers stand outside with Saito until he gets his stuff and goes home completely shaken up. My JTE is still screaming his name, still saying "what the fuck did you say?? get back here!! fucking get back here and talk to me! you're not even a part of my fucking grade!! Let me go let me go!!" He's then restrained onto the floor, screaming and crying, by 4 or 5 teachers. This goes on for 30 minutes. He's kicking and punching out, trying to wiggle free from being held fully on the floor whilst the school nurse tries to talk him down. The owner of the pub is also shook up but thankfully does not call the police, and someone calls a taxi to take my JTE home. When the taxi arrives, he's still inconsolable and shouting for Saito and having to be pulled into the taxi screaming and kicking, even though Saito had been gone over 40 minutes at this point. The 23 year old female teacher is crying, because she feels bad for Saito since she brought up the time and I am trying to reassure her that she did nothing wrong. Needless to say that once the JTE was in the taxi and it had drove off, we all went home after that.

Now comes the question, what the hell is going to happen on Monday? I am scheduled to have two classes with him - one second grade class and a special needs class. The special needs class is me, him, the 23 year old female teacher, one of the male teachers that restrained him, and a teacher who wasn't there - and five special needs kids. It's a small, intimate class and I'm really not sure what's going to happen.

I don't even know if there will *be* a class, as the whole thing was so atrocious. It was genuinely frightening. If the teachers hadn't restrained him in time, he absolutely would have attacked Saito, and also probably would have hit me in the face with his elbow when doing so. The JTE is also the head of grade, and on the way home from the izakaya a teacher mentioned he will probably have to step down from that position.

I genuinely don't know what to do now going forward. It was an absolute shit show. My main concern is that I have to work closely with him as his ALT, and I genuinely don't feel comfortable now. He will probably try to apologise to me on Monday, and I really don't know how to respond. I don't want to accept his apology and say it's okay because it's not, but I also have to think from a professional standpoint and a cultural standpoint too. There's also the students to consider. There is also a high chance he will be transferred in April but I am not 100% sure, but either way I'll be transferred to another school in August as per my contract.

If you were put in this situation, how the hell would you handle it? I am at a complete loss. Any advise is greatly appreciated.

TLDR: my JTE has anger issues, got drunk at a work nomikai and tried to attack a teacher. He was restrained by several other teachers and was screaming for 40 minutes. I have class with him on Monday and don't know how to handle the situation going forward.