Estelliu is relativally unique case. They are green star (as we know), processing a puppet like doll. They seem to have some sort of connection to Mariu. They are usually sweet and kinda

The voice I'm looking for is a something of a semi-whispery voice (not too whispery though). If you want some sort of reference, you can watch how I try to voice them in episode two (except improving upon how I did it.)

(EDIT: Hi, I almost forgot to mention that if you don't feel like watching an entire episode, I can at least say the range I am looking for is mid to slightly low range)