Backstory: Following the rising popularity of Hatsune Miku, "Vippers" (Vip News Bulletin@2ch users) schemed a troll "new VOCALOID release" as an April Fool's joke. Sen (線) provided the rough sketch and Nobuyo Oyama, a spoof for Doraemon's former voice actress Nobuyo Ohyama, provided the vocal. The Teto project continued after the troll campaign, and her vocal was recorded again for the use on UTAU, which vocal synthesis software was released two months earlier. UTAU and Teto were both unnoticed among VOCALOID composers at first, but during the last half of the year of her release several creators started composing songs for Teto, causing her fame to be established during following year. The voice provider's name reading was then changed to Mayo Oyamano (小山乃 舞世 Oyamano Mayo) to avoid unnecessary confusion.<br /><br />Teto was given official acceptance to piapro on Apr. 1, 2010, and to Project DIVA on Oct. 10, 2011.