Flash Marriage with Mr.Billionaire

Their marriage is a deal without foundation of love.
"Hey! Don't forget the agreement we made, it's just a fake marriage!" She stopped him and said nastily.
"Of course I know, but our marriage certificate is real, isn't it?" He chuckled mischievously.
He is not only the CEO of the consortium but also has a relationship with the mafia. He looks mysterious, aloof, and unapproachable, but actually, he is devious, tsundere, and narcissistic!
She thought he was a gentleman, but after getting married, she realized that he was definitely a complete beast!