Yuu's father's factory faces bankruptcy after a fire, forcing her to accept a loan from her father's former business associate, Tatsuro. As a condition for the loan, she is pressured into marrying his son, Makoto. With no choice, Yuu agrees and becomes part of the family. She spends her days overwhelmed with caring for the ailing Tatsuro and handling household duties. One day, Makoto, arrogant and domineering, picks a fight with her and begins treating her as his personal plaything. When Tatsuro notices Yuu collapsed and exhausted, he tenderly nurses her back to health—but his eyes hold a strange, unsettling glint.