卡塔莉娜·庫萊耶思因頭部被撞擊而取回了前世女子高中生時的記憶，意識到自己成為了女性向遊戲中登場的任性又傲慢的反派千金一角。在遊戲中她的最好結局是「流放國外」、最差結局是「死亡」，為了避免這些破滅旗幟，卡塔莉娜展開了行動。

卡塔莉娜為了避免「破滅旗幟」而苦戰著。某日，在被邀請參加的茶會上，卡塔莉娜遇到了侯爵千金瑪莉・杭特。兩人在談論了耕作的相關問題，卡塔莉娜因此和擅長照顧植物的梅麗親近起來，但是卻與瑪莉的未婚夫第四王子亞蘭・史提亞德發生了爭執，卡塔莉娜向王子發起了挑戰。

卡塔莉娜終於遇到了女性向遊戲的主人公瑪麗亞·坎貝爾，為了再次努力避免出現「破滅旗幟」。在充滿魅力的瑪利亞面前，卡塔莉娜畏縮不前，並誤以為吉奧多和基斯已經被瑪利亞攻略。聽不進去課的卡塔莉娜召開了慣例的「腦內會議」。

雖然卡塔莉娜完全被瑪麗亞的魅力迷住了，但依然在院子裡幫助了被邪惡的大小姐們包圍的瑪麗亞，也因此與瑪利亞加深了感情。之後，卡塔莉娜在假期期間去田地時得知了瑪麗亞的老家就在附近，卡塔莉娜決定順道去趟瑪麗亞的老家。

順利嗎？為了迴避毀滅旗幟的卡塔莉娜，從蛇的玩具的投擲練習和田地工作，到爬樹為止，一邊進行著迴避即將到來的「毀滅旗幟」的準備，一邊享受著充實的暑假。從來玩的吉奧多那裡聽到「一起去湖邊吧？」受到邀請。想和卡塔莉娜兩個人一起度過的吉奧多……

暑假也結束了，卡塔莉娜他們接受了魔法的實際技能考試。據說如果帶回作為實際技能考試的會場訪問了的「古的遺蹟」裡頭被放置了的「宿有魔力的石頭」合格…。卡塔莉娜和吉奧多、基斯、蘇菲雅三人，被設置了各種各樣的陷阱，進入了錯綜複雜的迷宮。

On her way to the east building library to find some reference books, Catarina joins up with the usual gang, and they decide to have a study session together. Then she opens a book that caught her eye... and it suddenly fills the room with light, then swallows her up along with Geordo and the others. Only Mary and Maria are left behind, so they cautiously open the book to try to rescue Catarina and the others trapped inside.

Anne Shelley is Catarina's personal maid, and is dedicated to serving her every need around the clock. Catarina is always surrounded by friends and laughter, but she's completely oblivious to the feelings that they have for her, which seems to have caused some misunderstandings. With no knowledge of how much Anne worries about this, Catarina decides to host Mary, Sophia, and Maria for a pajama party.

Catarina is suddenly faced with her own "judgment event." The cafeteria is abuzz, leaving Catarina's mind in a panic as she suspects her doom flag has been set at last. Then Geordo appears with the members of the student council. The noble girls continue to condemn Catarina as the student council members read the evidence they compiled against her. Then Maria, the alleged victim, speaks...

There's still no sign of Maria anywhere, and now Catarina has fallen into a deep sleep during which she dreams of her past life. Meanwhile, Geordo has a doctor examine her, but is disheartened when no cause can be found. As Catarina continues to sleep, all of her friends come to terms with their own feelings.

Catarina and the others have found the imprisoned Maria, and at last they confront the one behind her disappearance. How will this confrontation end?! Catarina has worked so hard to avoid her own doom flags all this time, and now she faces a crisis! And then the final event in the game, the graduation party, begins. Will Catarina make it through to the end without setting any doom flags?!