On top of the problems having two additional Knights of the Round attending Ashford imposes, Lelouch is shocked to find that Sayoko, disguised as him while he was away, had not only kissed Shirley to maintain the secrecy of the OSI control room, but set him up on dates with over a hundred girls the following day. Shirley, likewise, is shocked to find her "Lulu" dating multiple girls. She confronts him while he attempts to evade the dogged pursuit of several female classmates. To make matters even more complicated, Milly declares that for her graduation project, she would declare a "Cupid's Day", where boys would wear blue hats and girls pink hats, and if a girl steals the blue hat from another boy, they would be officially declared a couple!
Meanwhile, at the Imperial capital of Pendragon, the royal family, as well as the Knight of One, Bismark Waldstein, debate what to do with the now fractured Chinese Federation, with the majority advocating invasion and conquest. Bismark informs the emperor of the decision to invade the Federation to turn it into a new Area. All the while, Princess Cornelia, who had been missing since the end of the Black Rebellion, fights her way into the Geass Order's headquarters, determined to shed light on the wicked power that had compelled Euphemia to massacre the Japanese a year ago.
Back an Area 11, while Lloyd ponders what to do with the Guren and Nunnally reunites with the captive Kallen, Lelouch finds himself in an even more precarious situation: before Milly commences Cupid Day, she promises a budget increase to whoever obtains Lelouch's hat. Lelouch manages to switch places with Sayoko, who, disguised as Lelouch, evades his classmates with speed and finesse uncharacteristic of him. The school erupts into chaos as everyone from the horse-riding club to the glamour club, all the way to Anya in the Mordred, hunt down Lelouch. In the end, Shirley manages to get Lelouch alone when he saves her from the Mordred. She forgives him for acting so strangely, and takes his hat while telling him she'd like to get him to fall in love with her "for real".
Afterwards, Milly reveals she arranged Cupid's Day to help Lelouch and Shirley realize their feelings for one another. With that, she finally graduates, becoming a weather reporter for Area 11's news and ending her engagement with Lloyd (to the Earl's delight).
Shriley's newfound happiness comes to an abrupt end, however, when she falls under the effects of Jeremiah's Geass Canceler. Created and deployed by V.V. to undo the effects of Lelouch's Geass on the people of Area 11, the Geass Canceler causes Shirley's memories to revert back to before Lelouch used his Geass on her, causing her to remember that Lelouch is Zero, the man responsible for her father's death!
