In 1977, Shin Meiwa revealed that it had several ideas for its STOL flying boat concept on the drawing board, but ultimately none of these were ever built. They were the "Shin Meiwa LA" (Light Amphibian), a 40-passenger light amphibian for inter-island feeder service; the 400-passenger "Shin Meiwa MA" (Medium Amphibian); the "Shin Meiwa MS" (Medium Seaplane) a 300-passenger long-range flying boat with its own beaching gear; and the gargantuan "Shin Meiwa GS" (Giant Seaplane) with a capacity of 1200 passengers seated on three decks. Unlike the Shin Meiwa LA and MA which were like the US-1 in design, the Shin Meiwa MS and GS had their engines located in front of and above the wing to take advantage of the Coandă effect. In the end, none of the four designs got beyond paper studies.