This Guy is the Biggest Mistake in My Life

Satou Yui is an employee at Amagi Pharmaceuticals. Her beloved dog has died and she feels deep sorrow over its death. One day, while drinking at a bar, she shouts, with tears running down her face, "Develop a medicine to bring my dog back to life!" At that time, a man walks towards her. He makes a spiteful remark that there is no such medicine. He also tells her to stop barking and to go home. Yui feels anger within herself and she trips him. She then leaves the bar. Yui is unaware that the man she tripped is Amagi Kyouichi and he is the President of Amagi Pharmaceuticals.

The next day, Yui hears at work that the President is looking for her. When she gets to his office, she realizes the man she tripped in the bar is the President. She thinks that she might get fired, but he suddenly tells her, "Please treat me as your slave."