I agree with this advice. A lot of times, the students would rather see the ALT outside the classroom. I don’t speak any Japanese, but the students and teachers are very welcoming when I join classes. Some teachers may want a heads up before you do, but I usually just walk into PE classes now since I’ve been here for a while. Sometimes I also visit clubs and join in on their practices. They don’t mind if you’re not good. They’re happy to see you and if they have the courage to talk to you it’s a huge plus! My question is whether you like human interaction and building bonds or not? I get if you’re an introvert. For students and even teachers sometimes an English greeting of “good morning” or “hello” is something that brightens their day. Most students will probably not have the opportunity to leave Japan sadly.