Sentaro (Raizo Ichikawa) from Ipponmatsu sets out to commit evil and gain dignity, but his good-natured nature does not allow him to do anything bad. Along the way, Sentaro saves a young woman named Okimi (Yuko Miki) from a bad womanizer and meets a Yakuza named Katsugoro (Yoshie Mizutani). He then visits Katsugoro boss Kanjiro Inariyama (Ganjiro Nakamura II) to train to be a yakuza, but to his surprise discovers that Katsugoro is Kanjiro's only daughter, Okatsu. He also finds out that the young yakuza working in Kanjiro's house is his younger brother Hanji (Yukio Hashi). Then the Shigezo family, who had been annoying Kanjiro for a long time, set fire to his gambling hall!

Rainbow Over the Pacific is a tale of romance that moves from the streets of Tokyo to the islands of Hawaii as it weaves the story of two star-crossed lovers--Hideo (Yukio Hashi), an aspiring photographer from Japan, and Reiko (Jun Mayuzumi), a beautiful Sansei Cherry Blossom contestant from Hawaii--who are drawn together by destiny, yet appear to be fated to be apart. Will the sun set on their young love, or will it be the dawn of a new relationship?

A resolute young man searching for his mother, whom he was separated from as a child, defies a family who mistreat the poor and homeless.