can't remember the title

it was about high school girl and her parents/guardians died i think so she was proposed to by another boy from her school who works in real estate and they get married and start living together. he starts off really cold and is from a rich family and is on bad terms with his grandfather (which the FL helps resolve). obvi they eventually fall in love and he proposes to her with a flower ring and they honeymoon in hokkaido. can anybody help me with the title?