つきうさぎ is OSTER project's 3rd album. It contains 5 tracks, sung by ほんこーん.
The official album website is available here.
The regular album is purchasable on Amazon.
NOTE: None of the songs in the album are sung by Vocaloids, the album is here for information regarding OSTER project's works and to keep up to date with the album numbers. Sorry for any misunderstandings.