Kasamatsu (笠松町, Kasamatsu-chō) is a town located in Hashima District, Gifu, Japan.The Kiso River flows through the town, which is located in marshy flatlands and was often subject to flooding.[3] Per Japanese census data,[4] the population of Kasamatsu has remained steady over the past 50 years.It was an ancient settlement on the important river crossing connecting Nagoya with Gifu.Plans to merge with the neighbouring city of Gifu were rejected by a referendum in June 2004.