Kejo-numa, a marsh in Miyagi prefecture, is a great wintering site for migratory birds. More than 2000 Bean geese, which are an endangered species in Japan, winter there every year. The marsh was designated as a wetland under the Ramsar Convention in 2008. The name was suggested by T. Yusa.
Discovered on 23-2-1991 in Karasuyama by Inoda, S., Urata, T.