Cobalt Blue

Original title: 群青 愛が沈んだ海の色

Ryuji is a fisherman that has brought up his daughter Ryoko single-handedly. Ryoko and her childhood friend Kazuya have fallen in love. But when Kazuya dies in a tragic accident while diving for coral wood, Ryoko is overcome with grief and, emotionally destroyed, retreats into silent mourning.