Akihabara, Tokyo. This is where Japanese Pop Culture lives and thrives. Gadgets, PC parts, anime, manga, figures, dolls, doujin and more can be discovered here and if you dig deep enough you will discover gems like Leonardo. I always discover new stuff here each time I visit and now that I work here part time, it looks like I'll have the opportunity to make more of those discoveries.
I hear many folks ask "where are all the cute girls in Tokyo?"
Many folks answer "Shibuya or Harajuku" but I always answer "Akihabara" - Akihabara has cute 2D girlies *everywhere*
Akihabara is located on the JR Yamanote line (the green line). If its your first time to Akihabara then make sure you come with good walking shoes and also make sure you do some weight training or grow extra arms prior to your visit to help you carry around your loot.
The station however has some lockers which you can dump stuff in as you explore more parts of Akihabara. Many of the lockers operate using a SUICA - a card which you can use to pay for transportation (not taxi's) and food at many stores. Its like those Oyster cards in the UK.