The original version ran 143 minutes and was regarded as a "disaster film with brains," generally credited to the work of the two noted writers, Sakyo Komatsu and Shinobu Hashimoto. In the United States, Roger Corman's New World Pictures added insert shots featuring Lorne Greene and Rhonda Hopkins. Even with the added insert shots, this English dubbed version was cut down to only 82 minutes. This U.S. version concentrated on the action and special effects and removed those plot elements that were regarded as making the original version superior to many of the films in the then popular disaster genre. This U.S. version, re-titled "Tidal Wave" (1975), had a very poor reception in the United States.
The role of Prime Minister Yamamoto's driver was played by prolific supporting player/bit player/stuntman Haruo Nakajima. He would become best known for playing Gojira (Godzilla) in the original feature film series from 1954 to the early 1970s. This would be his final feature film appearance before his retirement, ending a known film career that lasted almost 25 years. When he passed away in 2017, his obituary was carried by the international news services, generally concentrating on his roles as the original Godzilla.
Lorne Greene was given name-above-title credit on prints of the U.S. version titled "Tidal Wave". His character doesn't appear until more than 45 minutes into this 82 minute version.
Allan Arkush edited the trailer for the shortened Roger Corman version called Tidal Wave. This was confirmed on a recent episode of The Movies That Made Me podcast