After her older brother dies, orphaned Teru Kurebayashi comes to depend on an anonymous friend, "Daisy, " with whom she communicates by text messaging. After breaking a window at school, Teru agrees work for the school custodian, Kurosaki, to pay for the damage, and she soon learns that Kurosaki is a demanding taskmaster who is hiding a secret, but he always seems to be near when Teru needs help.