http://shop.kotobukiya.co.jp/shopdetail/000000002782/ct430/page1/recommend/this is an example of a resin kit sold by koto but not produced by them. It's clearly stated it's resin.
><Product Description>>【please note】>This product is a color resin kit that requires processing by the user himself.>Some specialized tools and knowledge are required for processing of the resin kit.The anime FAGs are produced by koto, there is no reason to believe they would be resin and are not stated to be resin.
><Product Description>>Decided to animate! Limited edition of "Frame Arms · Girl" included plastic model Blu-ray Vol. 1>[Included Plastic Model Kit] Anime version Frame Arms · Girl Ramproad · Body>plastic>PLASTICNo note or caution about resin.
It is definitely not resin.
