I've returned from Japan. Here are some travel guides and budget travel tips, hoping they can help you 🥰

All typed manually, typos, please don't @ me.
First, the visa. Generally, apply about two weeks in advance (book flights and hotels after the visa is issued). If you find the process troublesome, you can use Taobao vendors who will guide you through the required materials. This time I used the academic visa (within three years of graduation).
Next, flights and hotels. For flights, choose midweek departures; round-trip is cheaper than one-way. This time, my round-trip with China Eastern was just over 2,000 RMB (about 300u). ANA requires waiting for deals... if not available, Air China is fine.
Then hotels. Do not book on domestic apps, and don't book last minute. Plan ahead, plan ahead, plan ahead! It will be much more expensive. Check out Agoda, Booking, Ctrip, etc.
For travel, you need to buy a data SIM card and a Suica card in advance (you can buy them upon arrival, but they'll be much more expensive). Then withdraw cash from a bank in advance as needed. Bringing a Visa card is also okay; local 7-Eleven stores have ATMs. If going to Tokyo Disneyland, getting a DPA (Disney Premier Access) will be more convenient.
Then download Google Maps in advance. You must download Google Maps; it's very convenient for taking the subway and finding restrooms. Also, remember to bring wet wipes and a small bag for trash. Convenience stores are almost everywhere (taking Tokyo as an example), so no need to search specifically...
For dining, most restaurants have tablets at the seats where you can choose your language and order. Payment can be made via Alipay, except some old-fashioned ones... Waiters can communicate in English, or you can use a translation device. Many expensive restaurants require reservations in advance; they really love reservations... At Tokyo Disneyland, we missed several restaurant shows this time because we didn't reserve spots in advance.
For accommodation, check-out in Japan is generally at 10 AM. Extra charges apply if you exceed the time. Luggage can be stored at the hotel front desk. APA hotels are convenient and cost-effective, but have historical issues. Also, don't stay overnight at internet cafes like Kaikatsu Club; the private rooms are cramped and uncomfortable.
That's basically it. Will add more if I think of anything else 🫡