Motokano to no Jirettai Gisou Kekkon

Haru is forced into a political marriage with Tamaki Rio due to the Isurugi family's situation. They live together in a formal, loveless arrangement, though both still have lingering feelings for each other. They attempt to act as if they no longer care for one another, but their emotions resurface as they spend more time together. The story follows their efforts to maintain the illusion of indifference while their attraction grows.