Hatsune Miku: Project Diva f on the PlayStation Vita has downloadable content that adds three new Vocaloids to the game—Akita Neru, Yowane Haku, and Kasane Teto. Sega have shared a video of the game that shows the three characters performing existing songs in the game:
Neru and Haku started out as unofficial fan-created Vocaloids, but proved to be popular enough that they were adopted as official characters with their own merchandise. However, neither one has an official distinctive voice, unlike the main Vocaloid characters such as Hatsune Miku and Megurine Luka.
Meanwhile, Teto does have a voicebank of her own, outside of the game, as she is provided as part of the UTAU synthesizer software in Japan. The DLC pack that adds Neru, Haku and Teto costs 600 yen in Japan.