Having married her childhood sweetheart, Riko now finds herself trapped in a relationship soured by infidelity. One day, by chance, she runs into her old friend Mr Takaoka, who offers friendship, love, and an unusual one—he teaches her the trick of living inside her dreams. Each night she sinks into another life—first as a high-ranking courtesan in the 17th century, then as a serving lady to a princess in the late Middle Ages. As she experiences desire and heartbreak in the past, Riko comes to reconsider her life as a 21st-century woman: as a wife, as a mother, and as a lover, and to ask herself whether, after loving her husband and loving Mr Takaoka, she is now ready for her third great love.