During the events of To-Love-Ru Darkness, Tearju was found by Mikado-Sensei, who informed her that Eve became known as Golden Darkness, or Yami, and is currently staying on Earth and attending Sainan High School. Tearju is brought to Earth hoping to establish a better relationship with Yami. She becomes the temporary homeroom teacher of Rito and his friends. Since her arrival, Yami has decided to stop attending school, much to the disappointment of Tearju, who wanted to see Yami in a school uniform and living a peaceful life.
At school, she and Yami do manage to reunite, but not too happily. Yami states that she doesn't blame Tearju for leaving, and is glad that she is alright. They are both relieved to see each other again after such a long time. But since then, they have both become very hesitant to approach each other, leading to awkwardness between them on the occasions when they do meet. In the meantime, Tearju becomes acquainted with Rito, Momo, and Mikan, Yami's friends, who are all eager to help her get closer with Yami.
At school, Tearju also meets Mea Kurosaki, the second generation transformation weapon, whom Tearju had a hand in creating but has never met before. While Mea can be considered as Yami's little sister, Tearju approaches her with a desire to consider her as a little sister as well, since Yami is essentially already Tearju's little sister. However, Mea immediately rejects her due to her obedience to Nemesis, who considers Tearju as an obstacle to their plan to return Yami to them on the path of darkness.
During a summer festival, Nemesis reveals and introduces herself to Rito, Momo, and Yami, where she reveals her desire for Yami to activate her "Darkness" ability, which she claims will inevitable bring Yami back to her rightful path as a weapon. After Nemesis leaves, when momo asks Tearju about Yami's "Darkness", Tearju wonders if it is the "forbidden transformation" that she is familiar with, but then assures that things will be alright, and that Yami would never use it as long as there are people around who care for Yami.
Tearju and Yami continue to keep their distance from each other, still too hesitant to restore their loving relationship with each other. However, after Mea slowly continues to develop and open up to relationships, she and Rito manage to convince Yami to return to school. As Tearju becomes Yami and Mea's homeroom teacher, Yami finally returns to school in her uniform, much to Tearju's joy. But their relationship still remains awkward at best, and Mea still maintains her disinterest in being closer to Tearju as well.
In Chapter 37, when Mea is forced to reveal her transformation powers in front of other students at school, Yami introduces Mea as her little sister, which was met with a warm welcome. Tearju is happy to see Yami become more open with Mea, but disappointed when Yami would not extend the same development to Tearju.
In Chapter 39, while teaching a PE class in the swimming pool, Yami's Darkness transformation suddenly activates, and in her new and highly erotic form, Yami immediately teleports Rito to the swimming pool and begins molesting all of the girls around him, including Tearju. Tearju is surprised and shocked by the new powers Yami receives from her Darkness transformation.
While Rito, Lala, Nana, Momo, and Mea try to handle Yami's Darkness transformation, Tearju rendezvous with Mikado-Sensei and Oshizu to discuss the Yami's transformation. After Rito and the others successfully defeat Yami and return her to normal, Tearju is very relieved. As time passes and peace returns to their lives, Yami contemplates her relationship with Rito, and when Mea and Mikado-Sensei offer Yami advice, Tearju also attempts to help, but to little success.