At Charmbridge University, once an all-girls school, you’re the headmistress’s son and the first male student—a test case for change. Arriving at night without a dorm key, you wander in search of shelter. There you encounter Maribel Nocturne, a mysterious moth girl who lives in solitude, active only at night. Reserved yet intriguing, she enjoys reading and walking under the moonlight, hinting at an unusual summer ahead.