of the manga series Ore no Vaccine dake ga Zombie-ka shita Sekai wo Sukueru (translated as Only My Vaccine Can Save the World from Zombie Apocalypse ) is a pivotal installment that further explores the series' unique and controversial premise. The story follows Yuu Oikawa , a 21-year-old shut-in who survives the initial zombie outbreak only to be visited by a mysterious woman named Sunny . Sunny injects Yuu with a "vaccine" that turns his body into a living cure, though the method for administering this cure to others is unconventional and highly adult-oriented. Plot Summary of Chapter 5