Ikemen Kadouka to Seiryaku Kekkon Shitara, Ishiki ga Tobuma de Mederaremashita

This story is about a young girl, Yuri, who was born into a prestigious flower arranging family, the Misono family. In order to pay of the debt her mother left, Yuri is made to marry Tsubaki, her first crush. Yuri, having admired Tsubaki from a far for ten years, is actually bewildered by the decision, To complicate matters, the dignified and beautiful Tsubaki is cold and won't even make eye contact with Yuri. On their wedding night, though, he kisses her sweetly as if deeply in love and ravishes her until she loses consciousness...

(Source: MangaPlaza)