Toki no Mahou ni Kakerarete

A letter arrives at Sara's bookstore announcing she has won a trip to European castles and a luxury spa, though she recalls no contest entry. Still hurting from past experiences, she resists the trip but is convinced to go by a friend. Upon arriving in the Kingdom of Carvania, she encounters Aleks, her former lover who disappeared five years earlier. He is now the prince and owner of the castle where she is staying. He takes her to a child's bedside, informing her she has been brought there to donate an organ to the boy—her son, whom she left behind years ago.