Be Naruto in Japanese.
Learn and retain the words you explore through deep dives into the most fascinating culture on Earth.
  • Stay immersed.

    Capture and learn vocabulary you discover yourself. No pre-built lists here.
  • Stay focused.

    The minimum you need to build your word collection, learn it, and retain it.
  • Stay consistent.

    Our spaced repetition algorithm balances learning the new and refreshing the old.
Learn at home, in the subway, and everywhere in between.

Small efforts count.
👋, I'm Jan.

Some people magically remember words after hearing them twice.
Not me. 😅

I made Kotobaten to help me learn and retain the words I ran into when exploring Japanese language and culture.

Since I started using it, it helps me learn around a thousand words per year.

I hope it can supercharge your Japanese journey the same way!