How should I move forward with my boyfriend, who is very strict about manners?

This isn’t about my papa (a male supporter), but I’m really struggling and would appreciate your advice. I’ve been dating my boyfriend for six months, and we had our first argument. I’m easygoing, while my boyfriend is very strict with himself and others. We ended up arguing first thing in the morning. We usually exchange “good morning” messages on LINE every day, but this morning I didn’t notice that he had already said good morning and started a different topic instead. He got angry and said, “Are you an animal or something that you can’t even say hello?” When I told him that the way he said it was harsh, he got even angrier and said, “You’re not reflecting on what you did at all.” He also gets angry over small misunderstandings, such as when I use polite Japanese incorrectly. I don’t mind being told when I’ve done something wrong, but when I asked him to change the cold way he gets angry, he said it was because I keep making the same mistakes. Until now, I’ve always apologized. But this time, for the first time, I told him, “When you get angry at me, I can’t say what I want to say and I end up feeling depressed. Honestly, I don’t have any confidence in myself anymore.” He said it was late and that we should talk again another time, then ended the call. He told me that in past relationships, he and his girlfriends never really confronted each other honestly, so they both kept things bottled up and eventually broke up. That’s why he wants to properly tell me the things he wishes I would change, and he also wants me to tell him what I’d like him to change. I’m sorry to ask about something like this, but personally, I think it’s difficult to change another person. I feel that it’s also important for both people to accept each other, and that if something really bothers you, it’s enough to gently ask the other person to work on it. I’m starting to feel anxious about continuing this relationship with him into the future, and I’ve even wondered if I should just leave. Based on your experiences, have you had relationships where you pointed out everything to each other and worked on fixing it, or relationships where you accepted each other’s differences (while, of course, gently communicating anything you wanted the other person to change)? Which approach do you think works better?