Hayate and Kusanagi, who share a strong bond, are popular students at their high school. However, Kusanagi's ambiguous behavior towards Hayate attracts unwanted attention. At a UFO-themed event organized by the student council, they unexpectedly come across Tatsumi, Hayate's sibling. Even though Hayate objects to Tatsumi's presence, their disagreement is abruptly interrupted by a UFO crash that vindicates Hayate's position without him realizing it.