Tool data and audio credits

Kana characters and memory hooks

Romanisation, reviewed look-alike pairs and memory hooks come from Niwa's in-house kana review data. The public tool snapshot contains the 228 kana items from the published hiragana and katakana course shards. Hooks are learning aids written for Niwa.

Stroke order diagrams

Stroke paths are derived from KanjiVG, copyright © Ulrich Apel and contributors, under Creative Commons Attribution-ShareAlike 3.0. The snapshot is pinned to revision 70a0b7ae0c18ceb5cb358274b029cce0234a43bc.

Niwa extracts ordered path data from the kana SVGs, removes the original styling and stroke-number text, and renders the paths with its own colours and animation. Combined sounds display their component diagrams in writing order. These extracted paths remain available under CC BY-SA 3.0; you may share and adapt them under that license with attribution and the same license for adaptations.

Download the derived stroke-path data and source information.

Pronunciation clips

The character buttons use the generated kana pronunciation clips referenced by Niwa's content-addressed course manifests. Niwa's content tooling generates these clips with Azure text-to-speech; they are not recordings supplied by KanjiVG or the dictionary projects. The stroke-data license does not grant rights to the generated audio. Third-party text-to-speech service terms govern use of the generated clips.

Audio is fetched only when you press play, from the configured Niwa content host. A missing clip produces a retry message rather than a substitute pronunciation.

Furigana converter

The furigana converter reads text with kuromoji.js under the Apache License 2.0, using the IPADIC dictionary it ships with; see the dictionary notices. A few whole-word readings are corrected with entries from JMdict, EDRDG, under CC BY-SA 4.0; the selected entries are shared under that license.

Vocabulary test

The vocabulary test ranks words by frequency in Tatoeba's Japanese sentences, under CC BY 2.0 FR. Its readings and meanings come from JMdict, EDRDG, under CC BY-SA 4.0; the word list is shared under that license.

Dictionary and other content

Other Niwa content uses sources including JMdict and Tatoeba. Their separate credits and licenses appear in the published content attribution file. Those licenses should not be inferred to cover the in-house hooks, generated audio or unrelated tool libraries.