Five vacationers and two crewmen become stranded on a tropical island near the equator. The island has little edible food for them to use as they try to live in a fungus covered hulk while repairing Kessei's yacht. Eventually they struggle over the food rations which were left behind by the former crew. Soon they discover something unfriendly there...

Akira Kubo
as Kenji Murai - Professor

Kumi Mizuno
as Mami Sekiguchi - Singer

Hiroshi Koizumi
as Naoyuki Sakuta - Skipper

Kenji Sahara
as Senzô Koyama - Sailor

Hiroshi Tachikawa
as Etsurô Yoshida - Writer

Yoshio Tsuchiya
as Masafumi Kasai - Owner

Miki Yashiro
as Akiko Sôma - Student

Takuzō Kumagai
as Doctor (as Jirô Kumagai) (uncredited)

Yutaka Oka
as Doctor (uncredited)

Keisuke Yamada
as Doctor (uncredited)