Kokoro no Kagi wa Dare no Mono?

When nineteen-year-old Nicola's father passed away, she married his business partner, Brett. She'd always had feelings for him, so when they married, she was over the moon. But her happiness didn't last. It seems that Nicola's father arranged the marriage before his death because he was worried that men would come after her for her money. The whole wedding was arranged just to protect her. As time passes, she knows that it's futile to wish for a true, passionate marriage with Brett, and with her twenty-first birthday approaching, she'll soon be able to give him back his ring and break things off... (Source: Renta!)