Marriage of Obligation, or Love?

"If you don't say anything, I'll just have my way with you. I'm still managing to keep myself in check now, aren't I?" Due to a sudden inheritance from a distant relative, Momoha is set to be engaged to Iori, the son of a generations-old prosperous family. She's thrilled that she'll be able to marry her first love, but is he just marrying her and making love to her out of his sense of duty??