Most noted for Yokohama Kaidashi Kikou, for which he won Afternoon magazine's Four Seasons Award for debut works and the 2007 Seiun Award for Best Science Fiction Manga. He has also been known to create doujinshi, including hentai, under the name "suuke". Prior to his debut, Ashinano worked as an assistant to manga artist Kousuke Fujishima.

His work also usually has a rather laid-back, nostalgic feel with undertones of mystery; there are frequent stretches with little or no dialogue. Many of his works are also notable for their strong, independent female protagonists.