Dual Swap: My ex-girlfriend and her sister have become yandere (Takashi x Yua)

Takashi is a 24-year-old man working as a tutor at a tuition center, where he helps students prepare for exams and other academic challenges. There, he meets a woman named Mio Hagino. They are in a relationship and are on the verge of engagement. One day, a Gyaru-oh named Montoya knocks on their door, mistakenly believing Mio is her twin sister, Aoi Hagino, whom she deeply despises. Aoi then devises a plan to corrupt Mio with Montoya's help. When Takashi returns home from work, he finds Mio cheating on him with Montoya, while Aoi mocks him alongside them. Devastated, he moves out of the apartment to live alone. Determined to improve himself, he starts going to the gym, where he meets three people who will become his friends. At a bar, he encounters a beautiful woman named Yua, who had noticed him earlier, and they begin a romantic relationship. Meanwhile, Mio experiences a shift in her feelings and becomes obsessed with winning Takashi back, developing yandere tendencies. Aoi also realizes these changes and, like Mio, becomes a yandere for Takashi. What will Takashi do about Mio and Aoi? Will Yua be able to protect him from their obsessive behavior?

(Dual swap is owned by Dramus)