Yeah okay, so this was during the time where I was obsessed with anime and attempted fanfiction. I won't bother mentioning the anime or specific characters.
The gist is: same universe as the previous season kingdoms. Our protagonist is the grumpy, antisocial, sole heir to the Winter (???) throne. Dragged out of bed by his overly-happy guard/guardian/bff (or whatever you call it), he is alerted that he must attend a social function. The only princess in the entire kingdom is finally at an age where she can be married off, and for some reason the kingdom of Autumn want him to marry her? Begrudgingly, he gets out of bed and goes about his day, preparing for the event. But he just wants to leave and be free and not a prince.
At the function, he meets another prince (wow!!!) and basically they hit it off. At some point he vanishes (there's something about water and a pool here?), ditching his fancy traditional robes and runs off... I believe he runs off to the summer district, staying in a sketchy hotel-like place. (His guard is from Summer?) His guard tracks him down and tries to convince him to go back.
Somehow, he is also tracked down by the Spring prince he met, and his guard. The two guards were apparently friends. So they go outside and hit it off. And then he has a deep af convo about why he doesnt want to marry this random girl and become a king. The Spring dude suggests that the kingdoms must join, but he doesn't have to necessarily marry the Autumn princess, as he, a royal of another kingdom, is technically also an option.
And then they join kingdoms and live happily ever after. I think. And the two guards also date or something. The Autumn princess is chill with this because she ships them. The main character prince is crowned Queen. The end. Lmao.