Emerarudo no Umi ga Nikui (1984)

Emerarudo no Umi ga Nikui 1984 / エメラルドの海が憎い 1984 / I Hate the Emerald Sea , エメラルドの海が憎い　貧乏なんてもういや！薄幸の美女が命がけで挑んだ真夏の海

Kumiko, a seamstress, works in a boutique. But everyone keeps telling her that she can do better. One day, a woman witnesses a murder, but the crime makes her dream come true, and it helps her, to become owner of the shop. Soon, fate causes Kumiko to start dating the deceased woman's ex-partner. But is it all a coincidence? (Source: XuongPhim)