Tell us your building and how you use the internet — we'll show what you can actually get (光回線 fiber, ホームルーター home router, or 格安SIM) and its true 24-month cost, in English.
Detached house (戸建て)Fiber is your call — but needs construction (工事).
Apartment with a 光コンセントOptical outlet already installed — fiber is usually quick and cheap.
Apartment — not sure about fiberCan't confirm a 光コンセント or that the building is 光対応.
Short stay / no permission to installCan't run a line — need something that just plugs in.