Sometime around now some mad scientist made a breakthrough, and implemented it through some virus or whatever through the air, water supply, or something that didn't matter at this point.
A few hundred years later the change had been normalized. The virus had made every human essentially both genders, but not. The potential to be female and their femininity was locked behind their dicks. So for most of their early lives kids were kinda stuck as boys. There were no girls, but thanks to puberty there were young women. You see somewhere between 12-14 usually boys will undergo the beginnings of puberty which includes a lot of the same things boys in our time get. A little bit of facial hair, B.O., more hair in general, an increase in growth, and genital development. However instead of just being able to jack off they also gain the ability to "Jack out" as some people call it.
After puberty a man can grasp his hardened dick, concentrate on it, and pull their dick out of their body. The penis as a hilt, scrotum as a handguard, and their very masculinity crystalized into a usually dull blade. As the dick blade is created with a man's dick and as much masculinity as they are comfortable giving up jacking out results in some physical changes such as breast development, enlarged hips, slight shrinking, and in general a transformation into a woman. Said changes can be completely reversed if the dick blade is "resheathed" into their now Vagina assuming the dick blade is still in one piece. It can be lost in many ways. Someone steals your dick while its out, a significant force hits the blade and shatters it, you just lose the dick blade, and then the Dick Duel.
Dick Duels traditionally is one man verses another man. They both grab and Unsheathe their dick blades at the same time giving up as much masculinity as they are willing to risk. The duel then continues until one of a few conditions are met. One blade shatters another blade, if this occurs the shattered pieces of the losing blade gets absorbed by the winning blade. Second one of the duelists gets their blade taken away, if this occurs traditionally the winner will absorb the entire blade. Third one duelist is able to insert their sword into their opponent's Vagina, this traditionally results in the loser having all their masculinity taken away but also rarely happens.
In society there are considered to be a few genders.
MM or Manly Men, Men who have won many duels display their member with pride. They can generally even lose a few significant duels and still be a respectable man
Men, Men who haven't won or lost a lot of duels and are just Men you'd expect from our time
Women, Men who have either lost all their masculinity or have chosen to relinquish their manliness. In general they tend to embrace their femininity in the way they dress and act. Although there are many who still carry their penis in a purse for either sentimental reasons or just to be able to take a piss standing up.
Futa, Their bodies are mostly female, their masculinity almost all but gone, but these sore losers still carry their penis' on their crotch in the hopes of maybe winning another duel. Whether or not the largest blade they can conjure be that of a dagger, the thinnest of rapier types, or none at all they have not given up on the pursuit of manliness... Whether or not they would be better off embracing their now mostly female selves.
Tradition is one thing, but as time passes fewer and fewer people care as much about the traditional gender norms or the etiquette of the dick duels. For better or worse.
Now we see the story of...