Japan is a country that has a lot of things to offer to tourists. And if you decide to visit, you will see that there are a lot of places to stay such as hotels and ryokans.
The Japanese culture is known for its hospitality, and people take pride in their way of life, so you will surely feel welcomed no matter what option you choose.
One such option is renting an apartment in the short term.
Depending on the location and size, this can be much cheaper than renting a hotel room, and it feels different too. You might not have all the amenities and services, sure, but you feel like you actually live there.
You will find apartments most easily in big cities like Tokyo or Osaka. While in the countryside, you are more likely to find houses for rent.
If you want to rent a whole apartment or house, or only a room, Airbnb is the safest bet for now. You will surely find something you like.