According to this article they were locked and one couldn't purchase a SIM separately. So no, they weren't SIM-less. https://en.wikipedia.org/wiki/Mobile_phone

According to this article they were locked and one couldn't purchase a SIM separately. So no, they weren't SIM-less. https://en.wikipedia.org/wiki/Mobile_phone_industry_in_Japan#NTT_DoCoMo https://en.wikipedia.org/wiki/Mobile_phone_industry_in_Japan...