ceruOS is the computer head, the body is just a transport vessel. the screen on its head is their only way to visually emote, so all expression comes from kaomojis, which change according to its internal states.

while capable of speech through a synthetic text-to-speech voice, CeruOS rarely uses it. they find it to be too artificial and deeply exposing. instead they communicate primarily through music that reflect their emotional state far more accurately than words ever could