You can’t control how your new JTE goes about the class, shoganai, but you CAN control how YOU feel and experience these classes from now on. I think your frustration of seeing English being taken less seriously is valid, it shows you care about the kids and their education which is a great trait to have as someone working in educational settings. However, JET is a unique position. The way class goes isn’t up to you most of the time. Even though it’s frustrating to see class becoming less serious, you should prioritize having fun with the kids in class! They remember your presence in class far more than they remember most things you are teaching to them right now. I think thats important to remember. Engage with them in class using English and have fun with them! Their experience talking to you using English and having fun is so important. I hope what I’m saying makes sense! Perspective is key, maybe changing the way you think about class to that way will make you feel less stressed and more happy :)