Are there any silly or interesting Itachi/Sasuke/other character headcanons you've always wanted to share?
Some of these will be Modern-AUish, some canon compliant, and some Akatsuki AU.
Whenever Sasuke sees something that's interesting to (only) him as a child he rushes to Itachi to share it. Itachi is his go-to person whenever he wants to share something. Itachi sometimes lets Sasuke's excitement slide because he's too busy/too tired, and little Sasuke is infuriated. He expresses his fury in form of stomping his feet, walking around the house with a pout. He keeps yelling in front of Itachi's room that no one loves him and genuinely looks sad. No one understands why Sasuke is acting so weird until Itachi picks on it and gives Sasuke some treat. It's super easy to please him.
Itachi is a bad cook. Sasuke is even worse. That's why whenever their parents aren't home, Itachi cooks and Sasuke waits instead of helping him. One time when Sasuke "helped", it almost invited disaster. Itachi swore to never let Sasuke in since then. Sasuke is super salty because what he did at 12 shouldn't be held against him, right? Itachi won't listen. Their parents have no idea about it. So, whenever Itachi cooks something in his millionth attempt, certain that he made the dish perfect, Sasuke always shoots him down with "I've had better". Though later at night he sneaks into the kitchen to finish the rest, because why not.
Sasuke likes to hang out with Madara, but he's always been scared of the old man. Sasuke says he looks good only when he's not speaking or smiling. He always hides behind Itachi whenever Madara is visiting them. Itachi often uses it against Sasuke when he won't let him finish his work. "Go to sleep, Sasuke, or Madara uncle will come." It's an inside joke and Madara is definitely not pleased because he loves kids. He doesn't want to be the bad guy in Sasuke's eyes.
Both the brothers love to go on long cycle rides, especially in summers.
Naruto and Sasuke have a lot of sleepovers. Whenever Sasuke has to go to Naruto's house, Itachi drops him there. And when Naruto has to come to Sasuke's house, they want Itachi to tell them horror stories. Not overly keen on scaring them both, he tries to evade, but Naruto wouldn't listen. To set the mood, all the lights are kept off, and as soon as Itachi starts, Naruto hides himself in covers, and Sasuke rolls his eyes. Although later at night neither Naruto nor Sasuke want to go out alone to pee. Sasuke is just as scared as Naruto. He just doesn't want to show.
Minato and Kushina love both the brothers. Because of them their families are super close as well. Occasionally, Minato would take all the three kids to some other city/fun place, and come home super exhausted, because Naruto and Sasuke are a menace.
When they're kids, and Mikoto and Fugaku have to leave for a few hours, Kakashi and Yamato have to babysit them. Kakashi hates it because he'd rather be reading his books, but Yamato loves spending time with them. He loves to spoil both the kids. Sasuke just ends up pulling Yamato's hair and also tries to pull Kakashi's mask. But he can't.
Itachi has a Danzo plushie, decorated with red marks and is beaten down badly as if Itachi likes to punch it every time he's mad. Mikoto is horrified because since when her sweet child become this violent. Fugaku gives Itachi a treat when he learns this. Sasuke just likes to pull Danzo plushie's ears because they're fun to him.
Sasuke hates Shisui and Izumi at home. They steal the time he can spend with his nii-san. But when Itachi is not home, Shisui takes Sasuke with him and they train and Shisui deliberately loses his matches. Sasuke tells everything to Itachi with glee that he defeated Shisui when they trained together. Sasuke grudgingly admits to himself only that he likes spending time with Shisui too, but he won't ever feed Shisui's ego, because his nii-san is still the best.
Kisame is another person Sasuke is scared of. But he gets to like him. If anything, if ever Sasuke is mad at his brother, Kisame sides with Sasuke, and tells his brother how terrible of a big brother Itachi is. One day, Sasuke spent exactly 30 minutes complaining about Itachi to Kisame. And obviously, Kisame lectured Itachi that evening.
Being Itachi's little brother, Sasuke is the unofficial member of the Akatsuki. He has his own tiny Akatsuki robe. He doesn't understand why he doesn't get "dangerous" missions like his brother does. They tell him he's the most important person in the Akatsuki, so he must get special treatment. They keep all the gory shit out of his knowledge.
Sasuke really, really dislikes Kakuzu. He also finds Hidan weird. He wants to protect his brother from Deidara because Deidara just seems like he's obsessed with his brother. Itachi must be protected from him.
The people Sasuke loves in the Akatsuki after his brother are Konan and Sasori. Sasori makes puppets/toys for him (without all the blood and stuff) and gifts them to Sasuke. Konan is like a mom to him. In Itachi's absence she takes care of Sasuke.
