Gyakuyunyū: Kōwankyoku

Gyakuyunyū: Kōwankyoku (逆輸入 ～港湾局～; "Reimport: Ports and Harbours Bureau") is an album by Japanese musician Ringo Sheena, released on May 27, 2014. It is a self-cover album, featuring new recordings of songs that Sheena wrote for other artists.

Each song also collaborates with a different famous Japanese music producer. Gyakuyunyū was the final release of Sheena's 15th anniversary celebrations, released on the day marking 16 years since her debut single "Kōfukuron".

The title is a reference to grey market goods such as grey import vehicles. Gyakuyunyū (逆輸入; literally "reverse import", commonly shortened to "reimport") is a term used on such scenes.