They have only one goal, to kill Akabane Koneko. One day, Ibuki Arakuni, a senior at Sousouji High School, learns that her classmate and childhood friend, Akabane Honeko, is being targeted by assassins. The mission he is given is to protect Akabane for a year without her knowledge, and make sure she graduates from high school safely. Thus began his school life as a secret bodyguard! But is there one more secret in "Class 3-4"...?! The new school action-comedy begins!!!