making later plans for summer

my trip to Osaka was great, i was only there for a week. i do plan to revisit in the summer time. i just have several questions

1) What site do i need to use to sign myself up to pass through customs with ease? i remember having to fill the delclaration form and such, i remember being told if i have signed up and have the qr code i didn't need to fill the form.

2) if i get a hotel along with the flight package, could i go visit other cities for few days before returning to my hotel? for instance; visiting himeji castle, kyoto, hiroshima, osaka (revisit), and mount fuji?

3) if i were to take about a month of visit to japan, do i need to have visa this time?

4) do i have to have a bus shuttle to get to mount fuji?

1) I think this is too early. The process of entering into Japan can change until you come in the summer. So please take information again maybe about 1 month before your trip.


2) Sure. Out of respect, just let the hotel know that you will be away for 1 night. But I dont see why you would pay for a hotel in Osaka if you are away for many days. If it is just 1 night, I understand that it can be more convenient to keep the hotel.
For Kyoto and Himeiji you can easily do that as day trip from Osaka. No need to get a different hotel. Hiroshima is potentially also doable as a day trip. Fuji-san isnt reasonable as a day trip.

3) If you need a visa this depends on your nationality, so without knowing that we can't answer this question. If you are from EU or US (and some other countries), then you don't need to apply for a visa, you get an entry permit valid for 90 days at the border.

4) https://www.japan-guide.com/e/e6905.html