恋と呼ぶには気持ち悪い

High-schooler Ichika Arima catches Ryo Amakusa, a twenty-six-year-old womanizing salaryman, just before he falls down a rainy staircase, and hands him her own lunch on the way to school. Ryo turns up soon after at the home of her best friend Rio, who turns out to be his younger sister, and announces that he has fallen for Ichika. He courts her in earnest with daily flowers and dinner invitations she calls, in her own word, kimochi-warui, and each rejection only seems to deepen his pursuit.