"Parallel Line" (平行線, Heikousen) is a song by Japanese pop singer Sayuri.

[1] It reached number 10 on Oricon and Japan Hot 100, making her enter Top 10 for first time in both charts.

[2] On 15 December 2016, Fuji TV's Noitamina revealed that Sayuri would perform "Parallel Line" as ending theme song for Scum's Wish.

The music video for "Parallel Line" was directed by Yasuhiro Arafune[3] and the storyboards were created from Scum's Wish's author Mengo Yokoyari.

[4] The video features Sayuri singing in front of mirrors with night sky and cracked glass effect.