Anne Clements is terminally ill.
She was born with an inoperable tumor in her head, and as a child, numerous doctors told her that she would not live to adulthood.
Ann's parents, seeing their frail and sickly daughter as a nuisance, sent her at an early age to St. Cecilia's, a posh boarding school for girls in the countryside: ostensibly to let the country air cure her, but really to get rid of her.
Ann's future looked bleak and bleak - but by some miracle she did not succumb to the doctors' predictions or her parents' pessimism.
Ann is now nineteen years old, and her condition seems to have stabilized, despite her frequent headaches. However, Ann spent most of her childhood convinced that she would die before her eighteenth birthday, so she has no plans, goals, or dreams, and has no idea what to do with what is left of her life.
Feeling completely lost, Ann decides to stay at her school as a teacher's aide, where she deals with the most challenging students.
Ann's work is fulfilling, but the monotony of her daily routine keeps her busy. As her twentieth birthday approaches, Ann is more and more eager to explore the world outside the walls of St. Cecilia's....
Then Ann meets a new nurse, Asaba Kohaku.
Kohaku is everything Ann dreams of: cool, confident, and independent.
Although, at first, Ann is afraid of the straightforward Kohaku, a relationship gradually develops between her and the school nurse. Kohaku tells Ann a little about her past, and Ann in turn opens up to her. Eventually Ann even begins to wonder if Kohaku is the catalyst she needs to get out of the prison she's put herself in for good.