>>1081969>>1082567It's a Sannow Sports Eminenza. Sannow was the in-house brand of a Tokyo bike shop run by Takahashi Nagoshira that was open from roughly 1960-1990, and Eminenza was the model name applied to their road frames. All the information I can find online suggests that Sannow frames were custom built, or at least semi-custom. Information about Takahashi and his brand is sparse online, but the brand was regarded well enough that he supplied Japan's track team with frames for the 1988 Olympics.
