Hanae Ashiya's first week of high school has not been easy—he has spent the whole first week in the infirmary, and his mysterious sickness is only growing worse. The unknown fuzzy monster that has attached itself to him since the day before school started is the source of his agony. Hanae comes upon a poster advertising an exorcist who expels youkai as his health deteriorates and the beast swells in size. Desperate and with nothing to lose, he dials the number and is directed to the Mononokean, a tea parlor that appears unexpectedly adjacent to the infirmary. Haruitsuki Abeno, a morose-sounding guy, reluctantly assists Hanae but expects money afterwards. Much to Hanae's chagrin, he is unable to afford the fee and must become an employee at the Mononokean to work off his debt. And to make things worse, his new boss is actually one of his classmates.