To find out if your area or any other location supports 4G or 5G (sub6 and 5G), you can visit this website: https://network.mobile.rakuten.co.jp/area
You can also enter the address or let the browser automatically find it based on your current location.
The image above is a screenshot from the website; I will explain each color used on this map:
The darkest pink area : This is the 5G milliband coverage area , offering extremely high speeds, potentially reaching several hundred Mbps. However, this coverage area is very narrow, usually just a small circle around the base station (as shown in the image below, there are three such circles ).
The medium dark pink area : This is the 5G Sub6 coverage area , which offers higher speeds than 4G but not as high as 5G Milli. Speeds can reach around 100 Mbps. The coverage area is wider but still not as wide as 4G.
The light pink area : This is the 4G LTE coverage area, which (according to the announcement) covers 99.9% of Japan's land area. However, the speed is only adequate, ranging from 20 to 60 Mbps.
However, these speeds are still more than enough for watching YouTube, Facebook, and TikTok, so you can rest assured. Of course, higher speeds mean smoother web browsing and other things :D
Okay. Once again, here's the link: https://network.mobile.rakuten.co.jp/area