In a world where magic is common magical girls battle for fun and entertainment! You happen to be a boy who joins with a group of magical girls. Warning: Game takes place in a highschool setting and some character may be as young as 16.
It's a typical CYOA, but a long and well-written one.
It's such an idealistic setting that I managed to make it all the way to the current end of content even while deliberately getting caught by all the "villains" (really just the other sports team) as often as possible, which means there's no penalty for trying to find all the sexy scenes.
That said, there's plenty of replay value because you can only pick two scenes out of several options for each in-game day...or you could use the back button to try them all before continuing down the path you like best. Each choice has several scenes attached to it that advance their own subplots if you choose that option on multiple days, so there are dozens of unique paths to take even if they all lead to the same end.
Lastly, although it's a bit of a personal preference, I'm glad all the gender transformations present are the complete package, rather than stopping halfway with futa or sissy themes.
I played this game back before it was part of tf games site, I believe, and I'm glad to see it's been taken back up. The story of a mischevious sister getting her younger brother involved in Magical Contests is an interesting premise. The writing is as good as Lily's other games as well. I would recommend this, especially if it's being updated.