オサナナブルー (Osanana Blue)

Background
Last Note.'s 12th published work. It tells a story about love between two childhood friends.

The song first appeared on the album IA THE WORLD ～Hikari～, where it was sung by IA. Later, a cover with GUMI's vocals was featured on Last Note.'s first album first trip, along with an original album exclusive music video by Hechima, which was available with limited edition of the CD. The PV was later uploaded to niconico. The song is also going to appear on Last Note.'s upcoming album Setsuna Code.

This song has entered the Hall of Fame.