Eventually, Tsunade had to put Sasuke in prison for a while and not letting you visit him even though you implored her not to do any of it.
Though, she explained to you that it was only a promise between her and the Kages and as soon as she finds a new Hokage to take her place, if she couldn't find any Sasuke would have to stay for at least 20 years.

"[name], what's wrong?" Kakashi asked as he entered your room. "It's Sasuke again?" he asked and you only nodded.
"If Tsunade won't find a new Hokage, Sasuke will probably stay in prison for at least 20 years. What am I supposed to do?" she asked. "She doesn't let me do anything, neither to visit him." the girl said as little tears started forming around her eyes.
"I'm sure she'll find someone." Kakashi said smiling under his mask and leaving your room.

▪︎▪︎▪︎

"What is it, Kakashi, that is that important?" Tsunade asked him.
"I have a request. Which is good for both of us." he said.
"What exactly?" she asked curious.
"I became the Hokage and you don't have to search for anyone to be capable of being Hokage." he explained.
"Why so sudden? I already asked you twice to be Hokage." she said thinking for a bit. "You do this for [name], right?" she asked Kakashi.
"Not only for [name] but also for Sasuke and the rest of Konoha teenagers. Sasuke did help us in the war and now he's in prison that won't make anyone wanna fight in any upcoming wars, if that's how we treat the one that fights for us." he said.
"I like your speech, but I like more when you act like you don't see [name] like your daughter. Your first reason is [name], am I right?" she asked and he nodded. "You should adopt her before she will marry that Uchiha boy. Plus you'll be the Hokage and it will be easy for you to adopt her after it." she said.
"I'll think about it but maybe she wants to keep her real father name." he said as he stood up.
"Then talk with her." she said as she looked at him leaving.

▪︎▪︎▪︎

"[name]!" Kakashi said your name as he enter his house. "I have a surprise for you." he said, hearing her coming down on the stairs.

"What is it?" she said excited.
"You have this expression since you were younger." he said.
"That's because you always make the best surprises." the girl said smiling.
"Then, I may present you the next Hokage." he said as he pointed his index fingers at his face, making your lips curve into a smile.
"You'll be the next Hokage?" she asked.
"Yes, I talked with Tsunade." he said, leaving the girl a little confused.
"You wanted to became the Hokage because of me?"
"Um... no?" he said surprised.
"I guess you did, since you say 'I talked with Tsunade' not 'Tsunade made me' which means you wanted to do it." she explained.
"Oh, come on, kid, I'm doing this for you and this is how you treat me?" he said smiling under his mask and patting her head, making her giggle.
"You seem like a dad." she said laughing.
"Well, I was going to ask if you want me to, you know, um, this is kind of embarrassing to say." he said rubbing the back of his neck.
"To adopt me?" she asked and he said a small and quick 'yes'. "When I was younger, I actually thought you adopt me." she said smiling. "But yes, I do want you to adopt me. It will make me very happy to know I don't have you only as a friend but also as a dad. And you know, sometimes family isn't a matter of the blood in your veins but the heart in your chest." she said smiling, making the older man to ruff her hair.