Tonarine Sai (隣音サイ)
Could be seen as a Vocaloid derivative character, but notable in that her songs are actually sung by a real person (Utaite) and modified to sound like a Vocaloid. The name was created because she thought her neighbors would say she was too loud, since the artist for Sai apparently records out of her bedroom. Tonari (neighbor) ne (hey!) Urusai (Be quiet! (you're being noisy)).