One interesting plot could be Naruto forgetting all his ninja skills. So he has to start from scratch, relearning basic jutsus. This would make for a great character development arc as he discovers his old abilities in new ways.
The plot could also involve Naruto's memory loss being a result of some sort of dark magic or curse. And the male character in the Yaoi relationship has to go on a journey to find a way to restore Naruto's memories. During this journey, they grow closer and their relationship deepens in ways it wouldn't have if Naruto hadn't lost his memories. Their shared experiences during this time create a stronger emotional bond between them.
Obviously Naruto himself is the central character since the story is about him losing his memories. Sakura would likely be involved too. She's one of Naruto's closest friends and a medic - ninja, so she might try to find a way to restore his memories.
The village elders might see Naruto's memory loss as a threat to the village if they think it affects his ability to protect it. They could try to keep an eye on Naruto and the male character he is involved with in the Yaoi relationship. This could create tension as the two just want to figure out Naruto's situation and develop their relationship, but now they have to deal with the watchful eyes of the elders.
Iruka - sensei could be one of those who help Naruto. He has always been like a father figure to Naruto and would offer emotional support. Rock Lee could also be a great helper. Lee, who has trained his body to be extremely powerful, could teach Naruto some physical combat techniques that don't rely on eyesight. And of course, the Nine - Tails inside Naruto might also play a role. It could potentially share some of its power or knowledge to help Naruto deal with his new situation.
One possible consequence could be a change in his fighting style. Without his eye, he might have to rely more on his other senses like hearing and smell, similar to how blind ninja in the Naruto universe adapt. For example, he could focus more on using his chakra to sense the movements of his opponents.
Naruto might also go through an identity crisis. His whole life has been centered around being a ninja with chakra and using powerful jutsu. Losing his chakra could make him question who he is and what his purpose is. He would have to redefine himself and find a new way to contribute to the ninja world. This could be a long and difficult process for him.
Maybe he starts to train with one - armed techniques. He could learn from other one - armed ninjas if there are any in the fanfiction world. His friends would also play a big role. They might encourage him to keep going or help him in his training.
His relationships with his friends like Sasuke and Sakura would be deeply affected. They might feel like they've lost a part of Naruto. Sasuke, for instance, might initially be frustrated as he's used to Naruto's determination. Now, with his memories gone, Naruto might seem like a different person to Sasuke.
A 'Naruto loses his memory fanfiction' might involve a mysterious curse placed on Naruto. He forgets not only his personal relationships but also his ninja skills. His sensei, Kakashi, could take it upon himself to reteach Naruto everything from the basics. Meanwhile, Naruto might form new, unexpected relationships with people in the village who don't know the 'old' him, and these new relationships could either help or hinder his journey to regain his memory.