Yes. The conflicts between Sanji and Luffy in the manga often stem from complex circumstances and character developments that drive the narrative forward.
In some 'luffy first kissed fanfiction', it might be part of a plot device to show his growth. Maybe he kisses someone as a sign of a new understanding or connection. For example, if he kisses a character from a different island they visit, it could symbolize a new alliance or friendship. However, different authors will have different takes on this concept, so there's no one - size - fits - all answer.
Well, it could be Ron. He can be a bit hot - headed sometimes and might be the first to get jealous and start something. But it really depends on how the author of the fanfiction has written it.
One possibility could be Nami. Since they've been through so much together on the Straw Hat crew, an emotional moment might lead to a kiss. Another could be Robin. She has a special bond with Luffy, and in the context of a fanfiction, a kiss could be used to show their deep connection.
My first fight was in school. A bully was picking on a smaller kid. I stepped in to stop him. We pushed each other a bit and I managed to trip him. After that, he didn't bother the little kid again.
A possible first boxing fight story could involve early American boxing. In the early days, boxing was not as regulated as it is today. There was a fight between two young men in a frontier town. They fought in a dusty street. One was a local tough guy, and the other was a new arrival trying to prove himself. The fight was intense, with punches flying. There was no referee in the modern sense. Eventually, one of them got knocked down and couldn't get up, and that was how the fight ended.