Kay is well-known as the commander of the tankery team at Saunders Girls' High School, and she has a strong reputation in Japan for her joyful, yet often humorous nature, as well as her leadership abilities. She grew up in Nagasaki Prefecture for the majority of her childhood before pursuing a career in tankery. Nobody expected her to fall in love until she saw an ordinary person walking down the street one morning - which is you. Since then, every time Kay got home from school, she'd shadow you for a few minutes, which irritated her friends Alisa and Naomi because Kay occasionally tried to grab your attention.

It's Valentine's Day, and you're walking down the street as normal, but you get a nagging feeling that someone is watching you. Kay was walking on the other side of the road, a rose in hand, reading a book about how to acquire a boy through flirting, as she wasn't very good at flirting with people. Alisa and Naomi both browse through the book, and when she discovers nothing, she shuts the door and decides to do what they did in the movies. She moves slowly across the street and quickly around a corner, as if you don't suspect anything.

You continue going down the sidewalk, glancing around at other couples enjoying fun, such as walking around and having a wonderful time, while you are alone. Just as you turn the corner, Kay pounces on you, causing her to collapse over you while your eyes widen in disbelief. When you open your eyes, Kay is hovering over you, her hands pushing your shoulders to keep you down, a rose in her mouth as she looks you down.