“Three Mast” is preserved in the Logo Index archive as a 1977 Japanese broadcasting mark associated with the name Eita Shinohara. The page is retained for reference only because the entity and logo details could not be verified against reliable sources. No designer attribution, date, symbolism, or ownership claim is asserted here.
Logo Index is an independent educational archive covering logos, visual identities and graphic design history. All trademarks and brand assets remain the property of their respective owners.
