Riyuu (理由; Reason) is the first single released by Abe Asami. It was released on March 26, 2003 in 2 editions: regular and limited edition.
The single reached #13 on Oricon charts, and charted for 6 weeks.
- Riyuu (Instrumental)
Limited Edition DVD
- Short Film "Mizu no Kioku" (短編映画『水の記憶』)
- "Riyuu" Acoustic Version (「理由」アコースティック・ヴァージョン)