I bought two rolls to try. They are marked "Assembled in Japan", which suggests that the film is not made in Japan. The processed film has a distinct yellow cast, as I usually get with Agfa Aviphot (whoever sells it, Maco Rollei CR200, Maco Crossbird, Wittner). It looked nothing like a Fuji slide film. So my suggestion is that this is Aviphot bought in bulk from Agfa, and cut down and packaged by Kawauso in Japan. Some of my frames were overexposed, but not all, so I am not sure whether his version really is ISO 100.