Disk Vol.9 "Strange Blue"
From Ephinea PSO Wiki
"Strange Blue" was created by mabuse as part of the Japanese Blue Burst servers one year anniversary celebration. Community members were able to submit songs to officially be included in the game. mabuse's submission described the song as, "Although the world of PSO never changes, each visit is a new experience. With this song, I hoped to convey that you're not alone. ".