The story centers on Toki, a princess, and Towa, the alter ego who shares her body. The two personalities each have their own skills and temperament, yet both are bound to the same man, Zack, whom they love. Rather than a grand quest to save the world, the tale turns on something more intimate: love, commitment, and the road to marriage. As their adventure carries them across time, the bond between Toki, Towa, and Zack is tested, and the complicated romance at the heart of their journey slowly comes to a head.