Hey guys churchy here again! I always pop in here when I can! Saw that this was being revived and I just went to London again last week for a NIN gig but went anime/manga/video game shopping too and found some extra places that might be of some use to you. Also I'll give you some feedback on the places you mentioned as since I first made this thread I have been to these places many times now.
One thing to keep in mind is that most of the best places for anime/manga/video games or anything Japanese is usually located in the city centre around the Leicester Sqaure, Picadilly Circus, Tottenham Court Road, Covent Garden area. Also because we are talking anime/manga goods and in London be prepared for a bit of a sting on the wallet sometimes!
Shops
Japan Centre is a really great store. They mainly sell Japanese food from light snacks and sweets (yes they do pocky and calpico) to proper meals and cooking ingredients, japanese cutlery on the ground floor. Then in the basement they sell a variety of books, manga and comics (in Japanese). But they do sell some English books on Japanese culture and Learning Japanese.
There are three main CEX (computer exchange) branches in london but only two are for games and other media. There is one in Tottenham Court Road and one in Rathbone Place. Both of them are very near eachother. However I recommned the one in Rathbone Place much more as they have more room, greater stock and a better anime selection in the basement. Plus it feels a bit more personal because it feels like a proper 90's store.
Oh just a warning with Tokyo Toys. They are moving shop soon (in about the next week or two) but they will still have a store in London (possibly another area in the Trocodero or somwhere near like Covent Garden when I talked to the owner) so if you find it isn't there don't be too surprised!
As said about Adanami shobo its located in the red light district and the banner at the top says they are a laundrette. They only sell things in Japanese that includes manga, CDs, some video games (even Snes last time I looked) but they also sell posters as well that are either rare promos or posters with rare artwork. Last time I picked up a nice Tenchi poster.
I know there is a hello kitty shop in London near the covent garden area if you're interested in that but I'm not sure where it is specifically.
Arcades
If you want an arcade to go to then there is a small but really good one next door to the CEX on goodge street. I found this completely by accident and it is AWESOME. It has some brand new and some good retro games. When you see it it looks like a small one with only about 5 machines but there are some stairs that lead down into a basement where the main games are. It also wasn't very busy when I went as well.
Games Include:
- Tekken 6
- Street Fighter (2, III Third Strike, IV)
- King of Fighters (The new number XII is in there and by the looks of it they hold tournaments on it!)
- Blazblue (the new fighter from the makers of Guilty Gear)
- Metal Slug (I know they definately have 2 and 3)
- Other old school
- A multi arcade machine with the likes of old school games like Ms Pacman
I actually preferred this to the big arcades in the Trocodero as it was not very busy so I could play the great games without having to wait hours and there was a great selection of old and new games for such a small arcade.
If you need maps to these places then there is a good guide here with links to maps.
http://www.otakunews.com/article.php?story=1457
Restaurants
Mentioned earlier in the thread someone gave the name of a place called Misato's. I have been several times and it is a really nice and cheap japanese restaurant with some good food in big helpings but beware it can get a bit crowded! If you want directions just pm me!
As a final note. You will probably find many Japanese restaurants just walking around London (I've found quite a few before) and you might find a few surprise shops just by walking around London so you might get lucky.
Anyway I hope you have an enjoyable trip and find some places that you like!
Pm me if you want any more info