In 1965, after publicly insisting he would never work in films produced outside the US, Adams began accepting parts in Toho kaiju eiga. His first Japanese movie was Frankenstein Conquers the World, in which he played Dr. James Bowen, a radiologist working in Hiroshima who encounters a new incarnation of the Frankenstein monster. Adams next starred in the sixth Godzilla film, Invasion of Astro-Monster, in which he played Astronaut Glenn, journeying to the newly discovered Planet X. In both film plots his character had a love interest with characters portrayed by actress Kumi Mizuno. Actors at Toho Studios later fondly remembered Adams as a "team player".
On the set of Monster Zero Adams and co-star Yoshio Tsuchiya (who played the villainous Controller of Planet X) reportedly got along well and played jokes on each other.Adams once asked Tsuchiya how to say "good morning" in Japanese but he instead taught Adams how to say "I'm hungry" (Adams was on a strict diet at the time and nearly fainted during filming). Later, when shooting a scene, Adams got even by saying to Tsuchiya in Japanese, "You're overacting!" Before leaving Toho, Adams wanted a picture of Tsuchiya, who at first thought he was just flattering him, but he said he really wanted something to remember him by. Before leaving Toho, Adams gave one of his formal outfits to Akira Kubo (who co-starred in Monster Zero as the meek inventor Tetsuo Torî) because, according to Kubo, "the suit fit me."
For a more detailed account of Adams' non-kaiju work and personal life, please visit the Wikipedia page: