It Starts with Heartbeat and Ends with Deep Love

His parents died young and he was brought up by his sister. In order to escape his sister's arrangements, he chose to escape and break out of his own world. She was the president of a group who pretended to be strong and cold. When they met by chance, he fell in love at first sight. She was wary. It wasn't until she survived countless desperate situations that she realized that he was always behind her! ...