"249.51" is an original song by Kuwagata-P featuring Megurine Luka. This song is a song filled with a lot of emotion. It is about two friends in a long distance relationship of 249.51km. This song was released as a single for Megurine Luka's second anniversary and is featured in the EXIT TUNES compilation album, EXIT TUNES PRESENTS Supernova 3. It has entered the Hall of Fame.