The heroine “Mitari Yo” is an elite worker in a shoemaking company, the hero “Ishida Ren” works in a real estate development company. They are classmates in university and had a bet between them: the first to get married would receive a red envelope of 300,000 from the other before her 29th birthday...... They were sure that they couldn’t be a couple and the hero started to pursue the female junior worker of the company to win the bet. The heroine also met her ex-boyfriend again and this is how the story started....