To type tsu in Japanese, use:

  • つ = tsu or tu
  • ツ = tsu or tu
  • づ = du

If you meant the small っ, that’s usually typed by doubling the next consonant, like kitte for きって. The voiced version of ツ is づ, and it’s typed as du on a romaji keyboard.

Quick examples

  • つ = tsu
  • ツ = tsu
  • づ = du
  • きって = kitte
  • つづく = tsuduku or often entered as tsuduku on an IME

If you mean “zu”

Japanese has both ず and づ , but most keyboards type づ with du , not zu.

Would you like the same answer for hiragana vs katakana?