Yofukashi no Uta

Kou Yamori seems like an ordinary middle school student, keeping up a pleasant façade with his classmates despite spending much of his time studying. One day, he stops attending school and develops insomnia, with no daytime routine to occupy him. Walking alone at night makes him feel better, though he knows that being unable to sleep is a problem. During one of these walks, Kou meets Nazuna Nanakusa, an unusual girl who suggests his restlessness comes from not feeling truly free in his daily life. She tells him he will not sleep until he is satisfied with how he spends his waking hours. After inviting him to her apartment to share her futon, Nazuna leans over the apparently unconscious Kou and bites his neck; he is only pretending to be asleep.