Amami Yu, a 24-year-old art restorer, and Ishigami Rin, a financial officer, are transported into the pages of a high-society thriller novel, The Caged Birds of Saionji, after blood splatters onto an ancient mirror. They awake in the bodies of the doomed sisters-in-law, Yui and Akari—each destined to die. But fate has given them a second act: Yu awakens a Golden Eye that can appraise and restore any treasure, while Rin gains the ability to read minds, piercing through the dark thoughts of her dangerously obsessive husband. Their plan is simple: rack up 1 billion yen in three months, then vanish. But when they find themselves falling for the cold-hearted monk Saionji Ren and the yandere painter Saionji Haru, they can't leave. Instead, they team up to expose a chilling conspiracy: the stepmother's scheme to drain the family of 5 billion yen, poison her daughters-in-law, and assassinate the patriarch. With the truth laid bare, the two couples—plus two children—escape to the Nordic wilderness, where they finally watch the northern lights together, bound not by fate, but by choice.
