Hotaru no Yomeiri

Satoko, eldest daughter of the respected Kirigaya family, is beautiful, graceful, and surrounded by marriage proposals, but a heart condition makes her future painfully uncertain. While she still hopes to find a husband who can ease her father's worries, she is kidnapped and placed before Shinpei Goto, a notorious assassin ordered to kill her.

Bribery fails, leaving Satoko with one desperate lie: she claims to have fallen in love with Shinpei and asks him to marry her. To her astonishment, he takes the proposal seriously and decides to protect her. Their escape begins with Satoko forced to maintain a romance she invented for survival beside a man who treats the promise of marriage with frightening sincerity.