Yes, there might be. The Naruto and One - Punch Man fandoms are both large, and it's not uncommon for fans to create crossover fanfics. In such a fanfic, Naruto could be depicted as a fan of Garou for various reasons, like being impressed by his fighting style.
One idea could be a story where Garou and Metal Bat are forced to team up against a common enemy stronger than they've ever faced. They start off hating each other but gradually learn to respect each other's fighting styles.
Once there was a girl named Lily. She was very into fitness. Every day, she would do hundreds of sit - ups and crunches. Her dedication to getting strong abs was amazing. She started from being a bit chubby but with her consistent effort, she gradually built up those abs. She often inspired other girls in the gym with her transformation story.
For a good character interaction between Garou and Saitama, start with their fundamental differences. Saitama is a hero who is bored with the lack of challenge, while Garou hates heroes. Have them start with a fight, but make it a comical one where Saitama's nonchalance annoys Garou to no end. This can lead to some great dialogue exchanges where Garou tries to taunt Saitama into taking him seriously, but Saitama just doesn't care.
The plot might involve Naruto reading about Garou in some kind of multiverse scroll. Intrigued, he uses his shadow clone jutsu to search for Garou. When they meet, Naruto is all excited and asks Garou a million questions about his fighting techniques. Garou is initially annoyed but then realizes Naruto has a pure heart and they end up having adventures together.
Well, fanfiction often takes elements from an existing source. In the case of abs120 fanfiction, it could be that 'abs120' is a code or name within a certain fandom. Maybe it's a story that expands on the adventures or relationships of characters associated with this 'abs120'. It could be a story set in a science - fiction world where 'abs120' is a technology, or in a fantasy world where it's a magical entity. There are so many possibilities.
I'm not sure specifically as it could be a fan - made fictional story related to Aladdin that focuses on his abs, perhaps it's a creative take on Aladdin's physical appearance in a new story written by a fan.