At the Star Kids Home, a combination group home/orphanage, a disparate group of children struggle with both the everyday issues of growing up and those specific to abandoned or orphaned children. Their one avenue of escape is the Sunny, a junked car that sits a little ways from the home. In the Sunny they can travel the world, go into space, or just find a refuge from the troubles of their world.

Sunny won the 61st Shogakukan Manga Award in the general category in 2015 and the 20th Japan Media Arts Festival Excellence Prize Award in 2016.

The series has been published in English by VIZ Media under the SigIkki imprint in hardcover format since May 21, 2013 and in Spanish by ECC Comics since October 29, 2015.

Sunny is based partly on author Taiyo Matsumoto's own childhood, during which he spent time in a children's home.