Question for people who have been to Japan

I’m planning to visit Japan in the next few months and I have some questions. I’ve already been to Japan 3 times but it’s been a while and I know some things have changed and I’m planning to travel a little differently than last times. Help will be super appreciated. I’m planning to go with a backpack this time and stay in hostels and guest houses to save some money. I know Japan is famous for their expensive costs but I know if you plan carefully you can have a great time for decent prices. First question is, which cities and towns should I visit? I’ve already been to Tokyo, Kyoto, Osaka, Fukuoka and Hiroshima and I’m looking for another cities or towns that are not super touristy but have hidden gems and a relaxed atmosphere. Should I visit any islands or stick to the mainland? <br><br>Secondly a lot of people say Japan has a lot of nature and hiking trails. I would love to explore those but it seems some are very far from cities and you need a car. Which ones are accessible with public transport? <br><br>Thirdly I’ve heard that some guest houses and hostels have curfew like 10 or 11pm. Will this be a problem? Should I look for specific ones that don’t have curfew? <br><br>Lastly how difficult is speaking English in Japan? I speak Japanese at a beginner level and I know it’s appreciated but I’m planning to stay for a while and not just a week.