国立天文台
In addition to being the theme song of Misia's Hoshizora no Live V Just Ballade tour, "Ginga" was also chosen as the official image song for the International Year of Astronomy and its music video, which features the position, size and distance data of stars and other celestial bodies, presented in 4-D, was created in collaboration with the National Astronomical Observatory of Japan. The song "Sukoshi Zutsu Taisetsu ni", which was previously released as a standalone digital single, was included as a B-side.