Since Naruto is full of energy, the Zanpakuto could have a constantly vibrating or pulsating appearance. The scabbard could be orange, like Naruto's jumpsuit. And the guard of the sword could be shaped like Naruto's hand with a Rasengan formed in it. This would be a unique and eye - catching design that would clearly show the connection between Naruto and the Zanpakuto.
Well, one way it could work is that Naruto's spirit or essence somehow gets trapped within Ichigo's Zanpakuto. This could lead to Ichigo having access to Naruto - like abilities when he wields the sword. For example, Naruto's shadow clone jutsu could be translated into some sort of sword - based ability where Ichigo creates multiple sword strikes at once that are illusions at first but can become real attacks. Another aspect could be that Naruto's strong willpower and determination influence Ichigo's relationship with his Zanpakuto. Maybe it makes Ichigo able to access more of his Zanpakuto's power more quickly or in new ways.
The female Zanpakuto could start off as a bit of a mystery to Ichigo. At first, he might not fully understand her power or her intentions. As the fanfiction progresses, she could gradually reveal more about herself, like her past and her true motives for being with Ichigo.
In such fanfiction, Ichigo's character might develop a greater sense of adaptability. Since he has a different zanpakuto, he has to learn new ways to fight and control his power. This could make him more resourceful in battles.
It could be a fanfiction that delves into the power dynamics. Since Ichigo has three zanpakuto, perhaps it shows how his power has increased exponentially. It might also be about the training he had to go through to be able to handle three zanpakuto, and how this changes his role in the Bleach universe.
One idea could be that the female Zanpakuto has a unique personality. For example, she could be sassy and constantly tease Ichigo while also being fiercely protective of him. In the fanfiction, she might have her own backstory, like being created from an ancient power that was sealed away for centuries until Ichigo awakened her.
It could completely change the dynamics of his powers and battles. Maybe a new Zanpakuto would give him unique abilities or force him to adapt his fighting style in unexpected ways.
One possibility is that Naruto would be very curious about the zanpakuto. He would start to experiment with it right away. He might try to infuse it with his Rasengan, creating a new and powerful attack. This would be a unique blend of Naruto's ninja skills and the power of the zanpakuto.
Yes, there is likely some out there. Fanfiction platforms often have a wide variety of creative takes on characters. You can start by checking popular fanfiction sites like FanFiction.net or Archive of Our Own. Just search for 'ichigo had female zanpakuto' in their search bars.
His friends might be in awe. After Ichigo meets his real Zanpakuto, his friends could be both amazed and a little bit intimidated by the new power he has. They would still support him, but there could be a new sense of respect and a bit of distance as they realize how much stronger he has become.