Maybe the plot is centered around a training exercise gone wrong. Naruto and Ino are participating in a special training where they are supposed to resist mind - control techniques. But Naruto fails and gets hypnotized. Ino then takes it upon herself to snap him out of it. She uses her own mental powers and her knowledge of Naruto's personality. For example, she might try to trigger his memories of his friends and his dreams to break the hold of the hypnosis.
One possible plot could be that Naruto is hypnotized by an enemy ninja who wants to use him against the Hidden Leaf. Ino, being a skilled mind - user herself, tries to break the hypnosis. She has to first understand the nature of the hypnosis, which might be a complex jutsu. Then she dives into Naruto's mind, where she encounters various manifestations of Naruto's fears and desires. Ino has to navigate through these to reach the core of his mind and free him from the hypnosis.
One possible plot could be that an enemy uses a new jutsu to hypnotize Naruto and then makes him target Ino. Naruto, under the hypnosis, starts acting strangely towards Ino, which causes confusion among their friends. The story could then revolve around how their friends try to figure out what's wrong with Naruto and break the hypnosis before he does something really bad to Ino.
Ino would likely be very concerned. She might immediately try to use her mind - reading skills to figure out what has happened to Naruto. If she can't break the hypnosis right away, she'd probably seek help from her teammates or sensei. Ino is a determined character, so she won't give up easily on saving Naruto.
A rogue ninja from a neighboring village could be the villain. This ninja might have a vendetta against Ino's family and uses Naruto as a tool to get to her. He hypnotizes Naruto because he knows Naruto is strong and his actions while hypnotized would create a lot of trouble for Ino and Konoha.
The plot could involve Ino being in a situation where she needs to understand the Sharingan to save a friend. For instance, if her friend was under the control of an enemy who had a Sharingan - based mind control. Ino would then seek out someone with knowledge of the Sharingan, like Kakashi. Together, they would try to break the mind control and in the process, Ino would learn a great deal about the Sharingan's capabilities.
It could also be part of a more complex plot where Naruto has made a promise to protect Ino at all costs. There might be a prophecy or some sort of dark force threatening the village and Ino is specifically targeted. Naruto, knowing the importance of her life for the village or for some other deeper reason, gives up his own life to ensure her safety. This could lead to a great deal of character development for the other characters as they deal with Naruto's sacrifice.
One possible plot could be that Naruto and Ino accidentally end up in a situation where Ino discovers she's pregnant. They then have to face the reactions of their friends and family in the Hidden Leaf Village. Naruto might be initially shocked but then quickly step up to support Ino.
Well, in such a fanfiction, the plot might involve Naruto using his charm and clumsy yet endearing ways to flirt with Ino. Maybe he starts by complimenting her flower arrangements in a really cheesy way. For example, he could say something like 'Ino, your flowers are as beautiful as you are.' And then Ino might blush and playfully push him away at first but gradually warm up to his flirting.
Well, it could be that they betray their village. Maybe they are tricked into believing false information about Konoha being corrupt. So they side with an enemy force, thinking they are doing the right thing.
A simple plot could be that Ino cuts her hair on a whim. Naruto is the first one to notice. He comments on how different she looks. This makes Ino self - conscious at first, but then she realizes that Naruto's comments are more of admiration. As the story unfolds, they end up going on a small adventure together where Ino's new haircut becomes an advantage in some situations, like when they need to blend in or move quickly without her long hair getting in the way.
Perhaps Naruto is trying to protect Ino in a really extreme way. He could think that there are threats to her life that no one else is aware of. So, instead of talking to her or her friends about it, he decides to take matters into his own hands and kidnaps her to keep her safe in a secret location. But this would obviously cause a lot of chaos among the other characters in the Naruto universe.