In Tokyo, the place to go and take your fill of electronics, gadgets, hobbies, games and cosplay is a district called Akihabara (often abbreviated as Akiba).  Located around a major multi-storey local rail crossroads station, it is easy to access from any part of Tokyo.  I bought an N scale Series 500 Shinkansen model railway starter set at a multi-storey hobby shop, then found a 240v – 110v transformer in a narrow back lane electrical parts shop so I could run my new trains back in Australia.