Mamoru Kagemori may seem unremarkable as a high school student, lacking in looks, athleticism, and intellect. However, his true identity as the heir to a centuries-old ninja clan dedicated to safeguarding the Konnyaku family unveils a hidden world of duty and intrigue. Tasked with safeguarding the mischievous Yuna Konnyaku, Mamoru navigates the challenges that come with his secretive heritage.