Most UI animation tools are designed and tested in English first. For Japanese products, a few details decide whether motion looks polished or broken.
Fonts and file size
A Japanese font covers thousands of kanji, so full font files are large. If your animation tool embeds fonts, subset them to the characters you use, or convert fixed headlines to shapes. For translatable UI text, keep it as live text in the app and animate the container.
Line breaking
Japanese text wraps between almost any characters, which can split words awkwardly, especially as containers resize during an animation. On the web, CSS word-break: auto-phrase breaks at natural phrase boundaries; MDN lists it as experimental, so check browser support and keep a fallback. Test animations at every width you support.
Vertical text
Editorial and brand work in Japan sometimes uses vertical writing. CSS supports it with writing-mode: vertical-rl, but many animation tools do not. If you need vertical text in motion, check support before you choose a tool.
Per-character effects
Kana and kanji are single characters, so letter-by-letter reveals work well, unlike scripts with combining marks. Keep them short in UI; long typewriter effects slow down reading.
Tools Japanese teams use
Figma is widely used for UI design, and STUDIO, a Japanese no-code web design platform, is popular for sites. For played animation, After Effects with Lottie export is common. For interactive UI that runs in apps, Rive and ExodeUI both pair an editor with runtimes. We make ExodeUI, and our site is available in Japanese. Whatever you choose, test it with your own Japanese copy before you commit.