try to visit as many onsens as possible, it was one of the best experiences i had in japan! there is nothing like soaking in hot water after walking around in the city all day - and it only costs 3-5€. if you've never been to an onsen you should look up a tutorial beforehand, because there are some rules that are important to know. i also suggest visiting an onsen in the city center for your first time, because they are used to tourists and are more likely to have english signs. i linked an article with some onsens in tokyo, i hope you try one and have an amazing time in japan!
