This is the original UserComment (UTF16):
Garten in Kyoto (Kyōto) (京都市) „Test“
With
exiftool -csv -csvDelim "\t" -UserComment *.jpg > out.csv
are the last Bytes in out.cvs:
0x1e 0x20 0x54 0x00 0x65 0x00 0x73 0x00 0x74 0x00 0x1c
0x00 0x74 is the 't' from 'Test', but 0x1c is not ok. Correct is 0x1c 0x20. The Hexdump of the Jpg ok! ExifTool delivered 1 Byte less (the 0x20).

This is the original UserComment (UTF16):
With
are the last Bytes in out.cvs:
0x00 0x74 is the 't' from 'Test', but 0x1c is not ok. Correct is 0x1c 0x20. The Hexdump of the Jpg ok! ExifTool delivered 1 Byte less (the 0x20).