How to Make C + V + CV (Csynth Reclist) UTAU Voicebanks Work in Three Steps
1. say you have [きっと]. It will be broken up as [ki] [t] [to]. If you have っ sounds (Hiragana C+V+CV only), it'll be [き] [っと] (No tut for the double consonant since it doesn't matter.)
2. Press P2P3.
3. Fix envelope errors and you're done!