Before Teru’s brother died, he gave her a special cellphone connected to "Daisy", a boy who would be there to look out for her whenever she needs someone. One year later and Teru continues to send mails to the mysterious Daisy, but she still has no idea who he actually is. One day, after accidentally breaking a window at school, Teru meets the rude school janitor, Tasuku Kurosaki, who insists she work off the cost of repairing the damage. But there’s more to this grouchy caretaker than meets the eye as in reality he is the Daisy who has been watching over Teru for all this time! With no intention of letting the lonely girl know his true identity, Tasuku must attempt to help Teru without being discovered, but can he really keep up the act, and just why is he taking care of her in the first place?