Japanese Koi or Gourami signed

This appears to have been framed circa 1940 or 1950 in Tucson AZ. Stamped and signed in Japanese. Help! I'd love to know the name of the artist. There is a second print as well, framed in the same manner at the same print shop in Tucson (The Picture Store on Stone Ave..now closed it seems). That one a name in English "Okada".