Saya is cosplaying as Miku Hatsune from Vocaloid 2. Vocaloid is a singing synthesizer application developed by the Yamaha Corporation that enables users to synthesize singing by typing in lyrics and melody. It utilizes Yamaha's Vocaloid synthesizing technology with specially recorded vocals of voice actors or singers. To create a song, the user must input the melody and lyrics. A piano roll type interface is used to input the melody and the lyrics can be entered on each note. The software can change the stress of the pronunciations, add effects such as vibrato, or change the dynamics and tone of the voice. Each Vocaloid is sold as "a singer in a box". The software is available in English and Japanese, although a Chinese version has now been produced for Sonika. Source: wikipedia
