Disclaimer: I don't own Avatar: The Last Airbender. If I did, you wouldn't see me here making fanfics-D.
The Gaang has already commenced Day of Black Sun, but the eclipse hasn't happened yet. They split up into two groups, Aang and Katara will infiltrate the Ozai's throne room while Sokka and Toph try to hold off as many Fire Nation soldiers as they can. Aang and Katara suddenly get attacked by an armada of soldiers. The two split up to fight the soldiers to try to hold them off while they make it to the palace, but they fail and meet up for a little bit to try to think of something else.
"This isn't going as we planned, we are heavily outnumbered," said Aang.
"I know! Do you have another plan?" asked Katara.
"No I don't, I was hoping you would…uh oh," Aang was interrupted by soldiers and they had to split up again to fight them off. Afterwards they got back together.
"Should we retreat?" asked Katara.
"I think that's a good idea…oh no, not again," Aang was again interrupted by the soldiers and they split up to fight off the fleet of soldiers and Firebenders. The two created steam to give them cover to retreat from the armada that outnumbered them. Toph made a tunnel for her and Sokka to escape from their problem, they decided to wait for the eclipse to come by and give them a huge advantage over the Fire Nation. Aang and Katara retreated to a secluded place where the Fire Nation would not find them for the time being.
"What are we going to do? Should we wait for the eclipse to come so we can just cut right through their defenses?" asked Katara.
"I don't know. I have been feeling that you shouldn't be with me when I face the Firelord," said Aang.
"What!? I can't believe what I am hearing. I always thought you wanted me by your side when you faced the Firelord!" Katara said in a small outburst of anger and sadness.
"Katara, I was doing some hard thinking yesterday about this invasion. Those thoughts involved me caring about you too much to let you get hurt by my responsibilities as the Avatar!"
"Aang, I appreciate the fact that you care about me that much, but you will need a hand in facing the Firelord."
"No Katara, I won't let you go with me." Aang then started to get a little sad.
"Is there another reason why you will not let me go with you? I think there is more to it than just you caring about me," Katara asked in curiosity with a little anger. Aang was silent for the moment thinking about what he should say at this point.
"I don't know if I want to say it right now," said Aang. Katara then gets close to him and puts a hand on his shoulder to try to comfort him and then told him nicely, "You can tell me anything Aang, you know that."
"I know, but…" Aang was just about to finish until Katara interrupts him, "Well then tell me." Aang then let a sigh out and started thinking about how he would say it.
Aang looked straight into Katara's eyes, "Katara, I don't want you to go with me to battle the Firelord because I care about you so much that I don't know what I would do if you got hurt."
"You pretty much told me that already. What's the other reason?" Katara asked in curiosity giggling. Aang then looked away embarrassed blushing.
"Well…I…I," Aang then looked straight towards Katara, but then looked away upset at himself, "I just can't say it."
Katara then tries to motivate Aang, "Aang, just tell me!" Aang then looks her straight in the eyes again and just says it, "Katara, I love you!"
Katara takes her hand off Aang's shoulder and just looks shocked from what he said, "What!!?"
"I knew it, I had the slightest feeling that you wouldn't like me like that," Aang complained.
"Hold on a minute Aang…" Katara tries to explain to Aang, but Aang interrupts her.
"It's okay; you don't have to like me like that."
"But you don't understand Aang, I love you too. You're the nicest and greatest person I have ever known. I know you would do anything to protect me, but I can protect myself you know." Katara then smiled and blushes.
Aang was shocked and blushing at how Katara felt for him, "Whh…What? You really feel that way for me?" Katara nodded her head in agreement and Aang kept talking, "I know you can protect yourself, but if something bad happened to you…I would never forgive myself knowing I could have done something to prevent it."
Katara puts her hands on Aang's shoulders turning him around to stare at her, "You don't have to worry about me, and it wouldn't be your fault if that happens to me. If something does happen, I know you will be right there next to me helping me feel better like I was for you when you got struck by lightning in Ba Sing Se." She starts to tear up slightly and then kisses Aang out of the blue. Aang is obviously shocked, happy, and confused at what just happened.
Katara then starts to talk while being embarrassed, "Well…that was awkward, but…" she then gets interrupted by Aang when he kisses her back.
"But you enjoyed it, didn't you?" Aang said with a grin on his face.
"Actually, yes I did enjoy it," commented Katara.
"I'm glad we had this time together Katara." As soon as he finished saying that, the eclipse started to happen and they didn't have any more time to talk and rushed to the throne room and began to face Ozai.