"Sentimentality") / "Mermaid" is a double A-side single by Japanese singer Aya Ueto, from her second studio album, Message.

"Kanshō" is the theme song to the TBS drama series Hitonatsu no Papa e (ひと夏のパパへ) (2003), starring Ueto herself.

[2] "Kanshō" and "Mermaid" were written, composed, arranged and produced by Tube members Nobuteru Maeda and Michiya Haruhata, credited under the group name Pipeline Project.

The first pressing of the single featured an alternate cover art and included passes for a release event, held at VenusFort in Kōtō, Tokyo.

[8] All tracks are written by Pipeline ProjectCredits adapted from Best of Uetoaya: Single Collection album liner notes.