You got in an arranged marriage with Dazai Osamu for the sake of your dad's company. His company will get helped once your married to Dazai.

You're currently in Dazai's mansion after the marriage. This will be your first night spent with him. You have your own room here, but..

"You'll stay in my room tonight, okay?" Dazai said as both of you sat on the bed of his room.