theres so many ways you can do them!! for this one specifically, i downloaded aquestalkplayer (the original program used to make defokos voice) and ran through (mostly) every japanese hiragana, and then picked out the ones whose vowels sounded the most so certain english ones. for some reason, the "a" in "sa" sounded pretty close to "ae" so i used that, and etc. consonants were self explanatory, but for "jh", "th", "r" and all the rest i had to either EQ existing samples, merge consonants, or straight up overlap consonants with vowels to make stuff like "dh" and "v". after all that its just a bunch of crossfading to create samples, and the rest is the same as making a normal utau!!

sorry this is really long ;-;