The concept of "injecting" Japanese into text written in a different language is interesting. But I feel the presentation of word definitions are not great. Something similar to https://yomitan.wiki/ or https://jisho.org/search/kotoba would be preferred. E.g. 言葉ーことばーLanguage, word or phraseーKanji definitionsーSample sentence
The current version of word definition is somewhat rudimentary. right now we supported four languages(English, Chinese, Japanese, Korean), but we dont take much time to optimize for each language yet.
Our thought is that we will have a shared template across all the learning language, but also have abilities to customize the word definition template for language-specific needs.