@ninechars the one I found you can read in english if you type
Japan Registry Services Co., Ltd. into google
it also says that .OR.JP [is for] Judicial persons (other than kaisha) established under the laws of Japan. [not organizations]
(e.g. EXAMPLE.OR.JP)
also
CO.JP Companies (kaisha) having an official corporate registration in Japan. Non-Japanese companies that are registered as “Gaikoku Kaisha” may also apply.
(e.g. EXAMPLE.CO.JP)
GR.JP Groups which consist of two or more individuals residing in Japan, or groups of two or more corporations [*2] established under the laws of Japan.
(e.g. EXAMPLE.GR.JP)
.JP Any individual, group, or organization that has a permanent postal address in Japan may apply for a 2nd level, i.e., General-use JP Domain Name.
(e.g. EXAMPLE.JP)
these 3 seemed to be the closest unless you want a regional subdomain.