Natsu harada

As she appears for the first time in the manga

A girl Kurono used to have a crush on in Middle School, that ends up dating his former bully Ryou Ikegami. In issue 282 she reveals she was in the class next to Kurono, but they never spoke. He dropped his student ID one day, and when she tried to give it back to him, he ran off as though he was afraid of her.

In issue 325 like many humans abducted she and Ryou were stripped of their clothes, but unlike some of their unfortunate abductees, that were sent to slaughterhouses as food, were instead taken to be exhibited at an alien zoo. Kurono meets both of them again, inside the alien zoo, and initially decides not to save them, hating Ryou. He then thinks better of it and shoots the transparent barrier to let them out.

In issue 326, whilst many of the zoo captives of making their escape, Natsu tries to get Ryou to come and hurry. They are nearly killed by a special ops warrior but are saved by Kurono.

After being escorted out of the alien ship by Kurono, she expresses her wish to stay with Kurono, asking him whether he still likes her and hinting that she may be developing feelings for the emerging hero. However Kurono leaves her on Earth with Ikegami to continue his search for Tae on the space craft.

In issue 374 Natsu and Harda now clothed, were seen walking in the streets of Tokyo, and spotted Kurono with Tae watching his comrades slaughter the last remnants of the alien invasion.