|Alias||Sarumane (Fan Name), Impostor|
|Japanese||Aizawa Mai|
D-ne (D音) is one of the female main protagonists. She had her debut in the song Aimless Imitation Chair Stealing Game.
- D-ne has long, purple hair with a red ribbon, similar to B-ko's, and blue eyes. She is mostly seen wearing her school uniform.
- D-ne is a quiet girl who admires B-ko a lot. She often compliments B-ko and tells her that she likes her. Despite her shy nature, she enjoys mocking at people until she hits a nerve. She is only nice towards B-ko and secretly makes fun of everyone else and particularly hates A-ya and C-ta for getting between her and B-ko. She is also quite blunt. She will genuinely express her feelings no matter the situation, and will seemingly go out of her way to do so. Despite this, she seems to lack a hold on her own identity, and even as a young child would attempt to copy the identities of those she loved. She also seems to be quite jealous, as when she realized she could not copy the object of her affections she would become angry.
- D-ne becomes very obsessive and cling to B-ko, similar to the behavior of a stalker, which is interpreted as being extremely creepy, showing that she is unable to compartmentalize those positive feelings in a normal, healthy way.
- D-ne revealed that she is in love with B-ko.
- Her only friend was a doll before meeting B-ko.
- Heavily implied to disliked men in general.
- "...I'll protect B-ko-chan. So... don't worry, alright...?" - (Warning of Impostors, Page 48)
- "But... I think it's wonderful that B-ko-chan has that dual nature." - (Lonely Hide and Seek, Page 42)
- "To me, she was my first real-life, perfect, ideal girl." - (Unknown source)