Ancient fairies known as personal friends, old rivalries that remain to this day, wars with no end, dragons with powers to destroy continents. All of this with humans in the middle of it hoping to live.

Gensokyo and academy city have many common enemies, the church hates them both, the gods do it too. ESPers are good allies but slack in tactics, something youkai are experts on.

Experiment, on the future of the Fate and touhou universes and how they would clash, magi are even rarer this days youkai are stronger, what would the grail war be considered for youkai and what Kirisames would be considered for the magus association?

One may know Gensokyo today, though it was not always like that. Many consider its origin to be Yukari, others the Hakurei maidens, while Kazami Yuuka is considered an origin too. It was a set of the right circumstances and the right people getting together at the right time.

How was Yuuka born and how she was raised makes us understand more why she is the youkai we know today.