1
geminate consonant (small "tsu" in Japanese)
拗音（ゃ ゅ ょ）と促音（っ）の出し方も、加えていただけると参考になるかもしれません。
I think it might be useful if you could add how to output the diphthongs (with small ya/yu/yo) and geminate consonants (with small tsu).