Yofukashi no Uta, also known as Call of the Night, is a captivating anime series that explores the life of a young insomniac named Kou Yamori who wanders the night streets. He encounters the mysterious Nazuna Nanakusa, a vampire who offers him a new perspective on life and the night. The series beautifully blends themes of self-discovery, friendship, and the allure of nocturnal adventures.