Momo möchte Rito endlich dazu bringen, ihrem Haremplan zu folgen. Anschließend versucht Rito, Yami und ihre Schöpferin Tearju wieder zusammenzubringen. Yami trifft eine Entscheidung, die plötzlich alles verändert ...
Yami wakes up to Luna the AI who asks about her change of heart. Yami replies that it's due to life at Sainan. Rito also wakes up to Momo. Momo is curious to see Rito's development towards her harem plan. She confirms that Rito is the perfect centerpiece because many girls have fallen for him. She also notes that Yami has gotten softer towards him. Rito questions Momo's theory as he sees Yami uneasy with Tearju. Momo and Rito then ask Mikado about Yami. Mikado notes that Yami cannot recall memories of her first visit in her office. Momo remembers Nemesis talking about Yami being unaware of her Darkness ability. Later, while Momo thinks about her harem plan, Rito speaks to Yami about problems with Tearju and hiding her past. Yami questions Rito's interest and tells him to back off. The meeting ends when he accidently falls onto Yami and gets unwanted attention. Later at the pool, while students examine Tearju's revealing swimsuit, Mea talks to Yami as sisters. Yami thanks Mea for inspiring her to start a new peaceful life on Earth. As Mea and Tearju agree, Yami feels a jolt as her body glows. Suddenly, Yami's transformation goes berserk. Mea is confused until Nemesis tells her that Yami is transforming into her true form: Darkness. Nemesis also possess Mea and locks her away ensuring the inevitable rampage and their future as assassins. Tearju, shocked, confronts Nemesis regarding Yami. Nemesis answers that Yami was created to fight and cause destruction. Admitting peace triggers this backup mode to protect Yami's identity as a weapon. Nana also demands Nemesis to return Mea's body but Nemesis lies that Mea has always been a false personality of her. Once the transformation is complete, Nemesis greets Darkness.
Constatant qu’Ombre continue d’être distante avec Tearju, Rito et Momo demandent au docteur Mikado des renseignements sur le passé de l’assassin légendaire. Le médecin leur raconte que lors de leur première rencontre, Ombre était blessée, sur les rotules et partiellement amnésique…
ティアーユとのことも含め、ヤミに幸せになって欲しいと語るリトに、ヤミの心は揺れ始める。その様子を知ったモモは、ナナや凛まで意識させるに至ったリトの誠実さに、改めてハーレム王の器を確信する。そして後日のプール授業。ヤミは晴れやかな気持ちで芽亜に、兵器であっても自分たちはここにいていいのだと語る。しかしその笑顔の瞬間、ヤミの中で何かが目覚める! 騒然とするモモたちの前で、ヤミ、そして芽亜の姿が変わり始めて…!?
이제는 몸도 마음도 완전히 지구 생활에 익숙해진 금빛 어둠. 그러나 그러한 금빛 어둠을 바라보는 불길한 시선이 있었다. 그리고 수영 수업시간, 드디어 사건은 벌어지고 마는데...
Yami se despierta con Luna, la IA, quien le pregunta sobre su cambio de opinión. Yami responde que se debe a la vida en Sainan. Rito también se despierta con Momo. Momo siente curiosidad por ver el desarrollo de Rito hacia su plan de harén. Ella confirma que Rito es la pieza central perfecta porque muchas chicas se han enamorado de él. También nota que Yami se ha vuelto más suave con él. Rito cuestiona la teoría de Momo cuando ve a Yami incómodo con Tearju. Momo y Rito le preguntan a Mikado sobre Yami. Mikado nota que Yami no puede recordar los recuerdos de su primera visita a su oficina. Momo recuerda a Nemesis hablando de que Yami no era consciente de su habilidad Darkness. Más tarde, mientras Momo piensa en su plan de harén, Rito habla con Yami sobre los problemas con Tearju y sobre cómo ocultar su pasado.