After Nagi Kurogane suffered severe injuries and started going through a long and painful rehab process, her twin sister Hayate decides to attend Tenshi Academy in her place. After being introduced to the academy's staff and other students, Hayate learns about the Hoshitori ("Duel for Stars") that many of the students participate in, collecting stars from the losers in order to gain higher wealth and status for themselves.
After witnessing a loner named Ayana Mudou effortlessly take down multiple opponents, Hayate returns to her orphanage at Dandelion Field only to find it abandoned and vandalized.
Chapter 2: The Lost Idiot
Hayate is told by a Yakuza man that the owner of the orphanage borrowed 8 million yen to keep the place going, and that they vandalized the building as punishment. With no other choice, Hayate promised to pay it back later, and after telling her story to her roommate Moka she decides to join the dueling students to earn enough stars (and therefore enough money) to pay off the debt.
Moka later hands her a list of potential partners for a Shinyuu, and Hayate decides she wants Mudou to be her partner after her performance the previous day. However, Ayana is busy with her video game and as in the previous chapter refuses to partner up with anyone. So she gives Hayate several meaningless tasks in order to keep her busy, but Hayate doesn't give up trying to convince Ayana to be her partner.
Chapter 3: When The Idiot Goes All Out
As Hayate continues her blunt overtures to Ayana, trying to become her partner, Ayana begins to have second thoughts about her loner stance. This doesn't stop her from smacking Hayate in the face whenever she becomes overly annoying.
During lunchtime, a former rival of Ayana's attacks her outside of a sanctioned duel in rage, but her blade is stopped by the student council president and her number two. Hayate then accidentally blurts out her real name, and the president decides to have a chat with her and Ayana. In her office, despite the fact that Hayate signed her name on Nagi's contract, she still allows both of them to be recognized as students of Tenshi Academy. But then she reveals her newest plan: The rival from before and Hayate will duel each other in a 2v2 battle. If Hayate wins, she gets to stay. If she loses, then she has to leave the school.