Ten years ago, Nakahara Asami's parents died in a car accident, leaving her an orphan. Since then, a mysterious guardian known as "Ashinaga-ojisan" ("Daddy Long-Legs") has covered her education and living expenses, on the condition that she study hard to become a doctor like her parents and never inquire about his identity. This year, she begins her first year of medical school. As she adjusts to a life separate from her boyfriend Katsumi, she meets classmate Moritsugu Shun and a handsome new professor, Hayasaka Tasuku, both of whom appear to harbor secrets of their own. What experiences await her, and will she ever discover who Ashinaga-ojisan truly is?