While on vacation in Hokkaido, Natsuki happens to meet Soichirou, a photographer. Unbelievably, she runs into him two more times completely by coincidence, and out of this, a great friendship is formed. He turns out to be the younger brother of one of her best friends, and they all end up living under the same roof. Three women, all unmarried, and all nearing age 30, plus 25-year-old Soichirou. Can a man and a woman truly be friends without ever falling in love? How large is the line between friendship and love, or does it even exist at all?