Three species of the unrecorded octopus and squids, Octopus megalops, Berryteuthis magister and Gonatopsis makko were collected for the first time from the East/Japan Sea in June, 2005. New Korean names proposed for these three species are "Big-eye octopus, Mako gonate squid, Schoolmater gonate squid" for the O. megalops, B. magister and G. makko, respectively. We report detailed taxonomic descriptions of these species.