Getting to Japan
Getting to Japan is generally quite easy. In many countries you can just book a ticket and go, but from others you may need a visa. A at the Japan National Tourism Organization lists countries that don't need visas, and the list includes the UK, the US and most western European countries.
From the UK
British citizens don't need a visa. Many airlines fly from the UK, but the only three that go direct are JAL, Virgin Atlantic and British Airways. Flying direct takes 11 to 12 hours. It's worth trying to get a flight that leaves around mid-day, as then you will arrive in the early morning and have most of the day.
Of the three airlines who fly direct, JAL has the best seats. Their economy class seats have 10cm extra leg room, which might not sound like a lot but makes a huge difference if you normally find your legs pressed against the back of the next row. All three offer an on-demand entertainment system, but the Virgin system seems to be somewhat older and with poorer screens. JAL and BA offer USB charging too, if you want to use your phone or tablet.
During your flight you will be offered a Landing Card, which you need to fill out. Remember to carry a pen! If you don't have one they are available when you land at the airport, near the Immigration counters.
As well as your name, nationality and passport number there are a couple of questions that you need to prepare for. Firstly you are required to write the address you are staying at, e.g. your hotel. Make sure you know the address, e.g. by copying it to your phone or printing it out. The address of Toukaisou is: 2丁目-16-12 Nishiasakusa, Taito, Tokyo 111-0035, Japan.
Secondly you need to state how much money you are carrying in cash. There is currently a limit of 1,000,000 yen in cash. Make sure you know how much currency you have on you.