During the Chunnin exams, in the Forest of Death, their team was able to be one of the first 5 teams to make it to the tower. During the prelims, Ran lost to Aya, and that made her want to train even harder.
Ran awakened her Mangekyou Sharingan when Sasuke left the village. During the night, when she was asleep at home, someone knocked on her door. When she opened the door to see a sobbing Sakura, she decided it was too late for her dramatics, and tried closing the door. That’s when Sakura screamed “Sasuke is leaving!” She didn’t take any moment to question Sakura or to not trust her words, she just ran out. She got to the gate in mere seconds but she couldn’t see him. Panic went through her body as she remembered the way Itachi left them both after knocking her and Sasuke out.
She activated her Sharingan and continued trying to find Sasuke. After 10 minutes, she saw him with 4 others, and she stopped in her tracks.
When Sasuke noticed her, he turned to his companions and told them to hurry and leave again. She tried to run after him while screaming his name, but she wasn’t fast enough and he didn’t even turn around.
“Why do you have to leave me too?!” She screamed before she collapsed on the ground, violently sobbing and shaking. Sasuke stopped for a second, but before he could even go to her, one of the Sound Ninjas’ stopped him. She left her there.
The one to find her was Shikamaru and his team, who woke her up in the middle of the day. Naruto, seeing her so dejected, told her that he was going to bring Sasuke back for sure. Before he could even finish the sentence, with her eyes fixated on the ground, she walked past him, even mistakenly bumping with his shoulder. She almost fell because of the lack of strength, but Neji and Choji caught her. When she got back to Konoha, she was called by the Fifth Hokage. She got interrogated like she was on with Sasuke leaving.
When Team Ayane came back from the mission she missed to take care of Sasuke who was supposedly still sick and in the hospital, she was called to the Hokage building once more. Seeing Ayane so angry without knowing what was going on, she broke down again.
Since all of Team Aya were Chunnins, they could go on missions without Ayane, as long as they were accompanied by a Jonnin, so when the Kazekage was kidnapped, they were on a mission with Asuma, searching for the Akatsuki. They didn’t know what happened in Sunagakure until they got back from the mission.
Itachi’s death: She joins the search for Sasuke not because she wanted to, but simply because she was assigned to. She wanted to protest, but once Aya and Ayane joined, she stopped herself from doing so. When they arrived at the place where Itachi and Sasuke were allegedly fighting, to absolutely nobody’s surprise, she ran to them. She wasn’t sure why the Akatsuki didn’t stop her, or why she even did that to begin with, but once she was there, she was met with Itachi fallen on the floor next to Sasuke, and Sasuke staring at nothing. With Ayane suddenly appearing in front of them, taking a hold of one arm of each of them and dragging them into her shadow, she didn’t get to say anything to Sasuke until he was at the hospital.
When Ayane told them the truth of that night, she had absolutely no idea how to react. Sasuke forced Ayane to leave his hospital room, and he stared at Ran. Ran left the room as well. She didn’t visit Sasuke at all while he was in the hospital, and when she found out that Ayane managed to make him stay in Konoha, she finally had a conversation with him. When Sasuke apologised to her, she slapped him across the face, and with that swing, her emotions exploded. They started living together again, much to her complaints, and the cold but warm relationship came back again, although it was very one sided.
During the war, she was with Sasuke when they saw Itachi, and they both followed him. While Sasuke was mostly silent, she asked a lot of questions that she needed answers to. “Why didn’t you tell us?” was the question that made Itachi finally look her way. Yet, he didn’t answer. After the whole Kabuto fiasco, when Itachi released the Edo Tensei, Ran found herself feeling extremely angry at everyone and everything. She wondered how she could protect Konohagakure when Konoha failed her and so many others.