KOTO FUUGA
Download her CV voicebank from this link
She was created by Rou and also presumably voiced by them, and released on November 3rd 2008. A CV 3.00 voicebank that notably contains extra phonemes. The voicebank is Kana encoded by default, Western users may need to manually encode Romanji.
The voicebanks install as a usual UTAU voicebanks. On windows, the average installation starts with having two windows open in the files app. One containing the UTAU program files [the folder inside labeled "voice"], and the other window having the unzipped file. You can drag and drop the folders you want to the UTAU voice folder.
Terms of use are as follows:
Impersonation/Misleading Copyright: Expressley Forbidden
Commercial Use of Voicebank: Permission Required
Commercial Use of Character: Permission Required
Limitations on Character/Voicebank: None Unless For Commercial Usage
Distribution: Free To Distribute, As Long As Credits Are Attributed
Original DropBox Upload: here
Archive.org Upload: here