Kagura realizes that she will not be able to take down Naraku on her own. Kagura knows of InuYasha's full demon brother, Sesshomaru, and approaches him one day. She asks him if he would be so kind to kill Naraku for her, in exchange for some sacred jewel shards. She wants him to "free [her] from his grip." Kagura explains that Sesshomaru is the only one who has the true power to kill Naraku. When Naraku is dead, Kagura promises Sesshomaru the whole sacred jewel in exchange. Sesshomaru asks Kagura why she intends to betray her father, and she tells him that she never wanted to be under his control. She insists that it would be a good idea for the two of them to team up together, but Sesshomaru doesn't agree. He tells her he doesn't have any interest in the sacred jewel, but he tells her to take the shards herself and use them to help her kill Naraku and free herself. Kagura gets angry and blames his refusal on being afraid of Naraku. Sesshomaru laughs and tells her he has no obligation to her, stating "if you don't have the resolve to go it alone, don't even think about betrayal." Kagura screams back that he is a coward and that she misjudged him, and flies away angrily.
Kagura is injured really badly by InuYasha's wind scar, and ends up floating down a stream by herself. Her kimono is ripped, and her breasts are out. She is dragged out of the water by Rin, Jaken, and Sesshomaru. She seems to have a bit of a desire to be around Sesshomaru after this part. Kagura also seems to trust them enough, especially because she has her guard down around them. She knows they have no intention of injuring her because they had full opportunity to kill her while she was weak. Jaken tells her to cover up because she is a lady that is indecent and exposing herself to Lord Sesshomaru, but Sesshomaru doesn't have any words for her. Kagura is convinced later on in the first season that Sesshomaru is definitely the only person who can kill Naraku for her, so she begins to worry that the deed will never be finished.
Kagura gets her heart back in the final act, and is stabbed through it by Naraku's poison. She falls off of her flume in the middle of a field of flowers. As she sits there, free at last, yet dying, she looks up to see Sesshomaru standing above her. He tells her that he followed the scent of blood and miasma. This leads Kagura to believe he was expecting to see Naraku's body, not hers. She asks him if he is disappointed that she isn't Naraku with a grin on her face. Sesshomaru looks at her and says, "I knew it was you." She smiles and thinks to herself, so you came, knowing it was me... Sesshomaru lifts up his Tenseiga a little, trying to see if he can save her from her death. Unfortunately, the sword doesn't react with her body, meaning that not even Tenseiga can save her. Sesshomaru looks at her and sees how close she is to death, which ultimately leads him to ask her if she is going to leave them now. She smiles and says, "Yeah, it's enough." She thinks to herself about how happy she was that she got to see him one last time before she dies. As her body disperses into the wind, you hear her calling out as the free wind. InuYasha and gang run over, and ask Sesshomaru if she died a peaceful death at least, and he says she does.
Kagura becomes a person that Sesshomaru is willing to save with his sword. This is kind of a big deal, especially because Sesshomaru doesn't just willingly go around saving anyone. Rin was his first exception, and for some reason, Kagura was the next. He didn't want to see her die, especially because she took his advice and kept on fighting until she got her wish. However, her wish ended up being the cause of her ultimate death, causing me to wonder if Sesshomaru feels a bit bad for not helping her accomplish the goal. Regardless, Kagura has obvious feelings for him because she was happy to see him one more time before she died. Sesshomaru must have had at least sympathy for her to show up by himself, especially when he knew it was going to be her in a dying state. I haven't read their relationship through the manga so I am not sure if it goes into more detail in the manga than in the anime, but their true intentions with each other are uncertain.