Shikyu No Kioku (2007)

Born into a wealthy family, 17-year-old Masato (Emoto Tasuku) has never been deprived of material comforts, but his distant relationship with his parents leaves him feeling empty. One day, Masato discovers that he was kidnapped by a woman when he was an infant. Curious about his past, he travels to Okinawa to find the woman, Aiko (Matsuyuki Yasuko), and ends up staying to work at her restaurant. As the two grow closer over time, an ambiguous relationship develops, not quite mother and son, not quite lovers.