An original character Yomogi often draws. Her full name is ζ馬ει³ (γγγΎ γγγ; Arima Senne), but Yomogi often call her δΉ³ηΌι‘γγ (Chichimegane-san; breasts and glasses). Phonetically read, her name means "There isn't, is there?".
Senne has long auburn hair, red eyes, glasses, a mole on her right breast near the nipple and a curly ahoge. Although, in some of Yomogi's early art of her, she is lacking some of these traits.
She is the younger sister of another character, Arima Senka.