Soshite Kimi wa Tsuki ni Natta
English name: And Then You Became the Moon
Type: Music, Episodes: 1
Aired: Jun 24, 2012
Source: Original
Rating: G - All Ages
Synopsis:
This song is about two best friends that are represented as the moon and the star. The song seems to be expressing a close friendship that also develops distance gradually.

(Source: Vocaloid Wiki)