Game Tanteidan is a Japanese shop with a large catalogue of video games. In the second floor of the shop you can find lots of complete MSX games (with box and manual), hard to find Konamis included, as well as games for many other platforms. They ship their products worldwide. By now the only payment method they accept are International Postal Money Orders. Visit their home page to see what they currently have in stock and send an e-mail (in English) to email@example.com if you want to buy any of their games, CDs, etc.
As you can see their sales lists are in Japanese. If you want to know which game is behind those japanese characters we recommend to copy and paste them into Tagoo or a search engine (like Google) to look for screenshots.
Relevant link: Game Tanteidan website