This is a FCS-only head mold. It was released at Tenshi no Sato in September 2016. The Full Choice Handbook: 2016 by Volks shows the head mold with 18/9mm eyes. This head was Sato exclusive, but became available to Tenshi no Mado and Sumika locations on September 18th, 2021.
Please click on the individual thumbnails to see the pictures full-sized.