Kanojo ga Mizugi ni Kigaetara
Mariko Tanaka, who works for an apparel manufacturer, is invited to a cruiser party by her colleague Yasuyo Ishii. The two of them get separated from them while diving with their party friends in Sagami Bay. While wandering in search of the original point, I accidentally find the wreckage of the plane Douglas DC-3 sinking deep into the seabed. When the two of them are in distress, they are rescued by Otsuka and Fumio Yoshioka of the yacht ship "Tsubame" who happened to pass by.