I intend this to be an English vocabulary building application. And I intend the main users to be Japanese people. In this app, users can build English vocabulary, linking words freely via etymology and semantics. And at the same time, users can brush up their Japanese vocabulary as well. So, this app is effective for the students of Japanese language other than Japanese students of English. This app is something like a so-called adventure-game. Using mainly etymological and semantical informati