What if Izuna had a fiancee?
Uchiha Izuna was born after a difficult labor. As it happened, a shrine maiden was staying nearby, and at Uchiha Tajima's urging, she helped Izuna into the world safely. In return, Izuna became the "fiance" of the shrine maiden's young apprentice. More than twenty years passed in the blink of an eye. Just as everyone had forgotten about the arrangement, the shrine maiden's apprentice came knocking.
"So you're my childhood husband?"
"Fire Release: Fire Dragon Technique!" -- from an Uchiha who was furious with embarrassment.
Theme: Everyone has the right to pursue happiness