I sold myself that day. A man and a woman share a kiss in a foreign city during Japan's Warring States period, swept up in the turbulent waves of history as they pursue freedom and remain true to their love. The husband is a Portuguese merchant, and the wife is Japanese, a slave.

The story follows Tatsu, a headstrong girl, who chases after Shino, a person she grew up with like family. Her pursuit leads her to board a trading ship at Nagasaki Port, where she encounters Leo, a fearless young man. It is aboard this vessel that Tatsu witnesses a horrifying reality: women forced into the bottom of the ship as slaves and subjected to vile acts by the crew. This historical romance weaves together the little-known historical facts about Japanese slaves during this era, depicting a couple whose bond transcends the brutal circumstances of their time.