My friend and I live in Japan and built a simple Japanese dictionary. It's not much but we recently hit 800 unique visitors in a month :) Feedback welcome, and the code is open source: https://github.com/gojp/nihongo

Nice product and very clean design. You allow for query by romaji, but could there be a way for you to output romaji as well?

Thanks. This has been requested before, but I didn't want to show romaji since it's generally considered a bad habit to learn Japanese with romaji (the "correct" way being to learn hiragana and katakana as soon as possible). But since people want it, we'll likely add it as an option.