Nagi is letting Nagisa get close to Kaito even though she is jealous because she is also getting closer to both of them, Nagi is also getting what she didn't know she needed, filling the hole in her heart from being lonely and not feeling like she could get close to anyone, now with Kaito, Nagi is feeling she belongs somewhere and is even getting closer to her adoptive family the way she has longed for all her life. Nagisa is so happy with the change in Nagi since she has the relationship with her onee-san she dreamed of, she also wants to be closer to Kaito since he is the one that brought her this happiness, she's acting like she has a big crush on him, she's afraid that he will disappear and she will lose her happiness. thanks for the story