The Anbu sister could be a powerful and mysterious character. In the fanfiction, she might have unique abilities that Naruto is curious about. Their meetings could be filled with tension at first, as the Anbu are often secretive. But as Naruto's friendly nature breaks through, they start to share their stories.
One possible fanfiction could be about Naruto forming an unexpected bond with Kurenai's sister who is in the Anbu. Maybe Naruto stumbles upon her during a mission and they start to work together, gradually learning about each other's pasts and dreams.
In fanfiction, the teen Anbu sister might be from a different clan. Her relationship with Naruto could develop as they face common enemies. For example, they could team up against a group of rogue ninjas. She could teach Naruto some new Anbu - like techniques that he hadn't known before, which would enhance his skills and make him more formidable in future battles.
She might convince him by showing him the long - term benefits for the village. For example, she could tell Naruto that in ANBU, he can prevent threats before they become major problems.
For Kurenai, her character could be developed by exploring her relationships with other members of the village more deeply. For example, showing how she mentors the younger generation in addition to her regular duties. In the context of ANBU, she could be given a role where she has to train some of the ANBU recruits. As for Naruto, if he is involved, his time in the ANBU could show his growth in stealth and strategy, which are different from his usual combat style.
It would be more nurturing. Kurenai could cook for Naruto, like making him some of her special ninja - style meals. And she'd be there to listen to his problems, whether it's about his love life or his struggles with mastering new jutsu. Their relationship would be based on mutual trust and respect, just like a real sister - brother relationship.
Well, it could be about Kurenai having some secret connection to Naruto as his sister. Maybe she discovers this truth and has to deal with the implications. For example, she might have to protect Naruto from new threats while also coming to terms with her new - found family relation.
Another idea is a story where Naruto joins the ANBU and is paired with Kurenai for a special undercover operation. They have to infiltrate an enemy organization that is suspected of planning an attack on Konoha. Along the way, they learn more about each other's pasts and develop a strong bond as comrades.
The Akatsuki could be the main antagonists. Since Naruto is an important target for them, and if Kurenai is now his sister, they might see her as an obstacle in their way. They could try to use their various powers and strategies to either capture Naruto or cause harm to both him and Kurenai.