"Pureness" is a song recorded by Japanese singer Aya Ueto, from her debut studio album, Ayaueto.

The look for the single's artwork and music video was based on Ueto's breakthrough role of Nao Tsurumoto on the TBS drama series 3-nen B-gumi Kinpachi-sensei.

Due to overwhelming fan demand, a second event took place at Zepp Osaka on September 15, 2002.

Ueto's first televised performance of "Pureness" was on the NHK music program Pop Jam Summer Special.

[4] It peaked at number 4 on the weekly chart, with 46,000 copies sold in the first week,[5] becoming the first debut single with no commercial tie-in by a female solo artist to reach the top five in over three years, since Kyoko Fukada's "Saigo no Kajitsu" (1999), which also debuted at number 4 and was coincidentally released by the same label.