Shinpi no Rasen (神秘の螺旋), translated as "Mystic Spiral", is a song performed by Japanese actor, Yukihiro Takiguchi. It is the ending song for Harukanaru Toki no Naka de 4; it can be found on one of the game's character drama and soundtrack CDs, Amesora no Shou. Takiguchi also voices a traveling bard in the game who follows the protagonist's party as a minor support character. He promises to someday sing about her adventures, which is the in-game's reason for having the song. An instrumental version plays during promotional videos and within various character routes.