Looks like you're having some issues with the text encoding. If you want to use classic UTAU, you'll need to ensure that the language for non-unicode programs is set to Japanese. This system setting is required before installing classic UTAU and any time you want to use it. Here's a setup and installation guide.
This tutorial will go over 4 steps to set up UTAU. Changing system locale Checking the decimal separator Installing UTAU Changing UTAU to English Changing system locale In order for UTAU to work correctly, you will need to set your system...
utaforum.net
Additionally, the oto.ini file should be saved with Shift JIS encoding. With more advanced text editors like Notepad++ or VS Code, you can select this encoding directly. If you're using Notepad, then select "ASCII" encoding. A text file containing Japanese characters saved on a system with Japanese non-unicode language will cause the resulting file to be encoded in Shift JIS.
Alternatively, OpenUtau is unicode-compatible, and will not require any special system setup:
http://www.openutau.com/