 The origin of the name is unknown, and many hypothetical etymologies exist.According to a passage of the Shinpen Kamakurashi, it comes from the (a term usually shortened into just "Shichiri"), which was an Edo period messenger service on the "Kantōdō" highway with a horseman change every seven "ri".However, since the expression "shichiri" also meant "a long ride", the name could also just mean that the beach is very long.