Missing Fairy Crisis
Premise: One night, on the full moon, all the fairies of Gensokyou went missing. The next day, Gensokyou is in an uproar. Investigations reveal that not a single fairy can be found. That night, a lone moon rabbit appears on Gensokyou, looking all beaten up, desperately seeking the one called Hakurei Reimu.
As a follow up to Silent Sinner in Blue, the Watatsuki sisters decide to punish Gensokyou for the loss of their fine vintage by kidnapping all fairies.
Far from being helpless, the three mischievous fairies use their teamwork to create an illusion that the Fairy Cage is empty, having no visual or aural confirmation of any fairies within its barriers to any observers. A rabbit guard, passing by on a routine patrol, open the cage to check and a torrent of fairies pour out, unleashing a fairy avalanche on the Moon that has at this point never ever even seen a fairy before.
Unknown to the Lunarians and everyone else on Gensokyou, the mysterious power of the full moon confers inexplicable boosts of strength to fairies exposed to them, and being on the full moon itself had an overpowering effect on their abilities.
In the eternal spring of the Lunar Capital, Lily White yelled "Spring!" and turns the beautiful capital into a botanical wonder as she flies around in delight. Lunar Child experiences a power boost unlike any other fairies and blankets the Moon in a field of communication blackout. Star Sapphire finds her senses stretching far and accurately over an area big enough to cover the Lunar Capital entirely.
Responding in a knee-jerk manner, the Lunarian forces open fire on the fairies. Regenerating in spans of minutes and being slightly drunk on power, the fairies fire back, leading to a breakout of conflict the scale never encountered or happened before. One would have assumed that the Third Lunar Invasion has arrived.
Unable to kill the fairies (lol), the Watatsuki sisters sends Reisen (II) down to Gensokyou in search for Hakurei Reimu to beg for help.
Storyline and Routes
Storyline A (Bring them home): Hakurei Reimu
Route Note: Reisen (II) made it to the Hakurei Shrine after escaping from Daiyousei's ambush.
A1: Reimu approaches the Scarlet Devil Mansion to request for Patchouli to make a rocket again.
A2: Reimu gains assistance from Yakumo Yukari to enter the Moon.
A3: Reimu goes to Eientei and requests for Eirin and Kaguya's help.
A1 Consequence: In return for assistance, Remilia demands moon rabbits as a new lineup of maids in the Scarlet Devil Mansion.
A2 Consequence: Yakumo Yukari forges a secret but permanent way to the Moon.
A3 Consequence: Houraisan Kaguya and Yagokoro Eirin are officially pardoned, but choose to remain in Gensokyou. Contact between the Moon and Gensokyou are formalized.
Storyline B (Get more home): Scarlet Devil Mansion Team
Route Note: Reisen (II) gets lost and ends up at the Scarlet Devil Mansion instead. Patchouli Knowledge provides access to the Moon.
B1: Remilia Scarlet as protagonist
B2: Izayoi Sakuya as protagonist
B3: Patchouli Knowledge as protagonist
B1 Consequence: Remilia Scarlet rescues only her maid fairies and the Named fairies and kidnaps several moon rabbits as maids. Relations between the Lunar Capital and Gensokyou sour.
B2 Consequence: Izayoi Sakuya rescues the Mansion's maids and the Named fairies only. The Watatsuki sisters continue to fight for several more months before catching on the nature of the fairies and stop fighting and sending them back to Gensokyou.
B3 Consequence: Patchouli Knowledge resolves the problem, demands access to their library. Comes back with several tomes, only to go missing days later.
Storyline C (Drag them home): Cirno
Route Note: Cirno is busy challenging Kirisame Marisa in Great Fairy Wars and trying not to get vaporised. Hence missing the spiritng event. Reisen (II) gets lost and Cirno bumps into her. Cirno approaches Hakurei Reimu for advice, told to piss off and find others.
C1: Cirno approaches Eientei, Houraisan Kaguya and Yagokoro Eirin volunteer to help. Mokou chases after Kaguya, Cirno follows behind.
C2: Cirno approaches Kawashiro Nitori, brings Utshuho Reiuji as fuel source and partner.
C3: Reisen (II) takes Cirno to the Lunar Capital.
C1 Consequence: Fujiwara no Mokou duels with Houraisan Kaguya over the Lunar Capital, completely ignoring the current crisis. Fujiwara no Mokou also discovers the real source of the Hourai Elixer, flies into a mad rage, duel becomes a matter of whether or not the Moon becomes a flaming orb. Yagokoro Eirin fends off the fairies with great collateral damage.
C2 Consequence: Utshuho Reiuji fights against Amaterasu-channeling Watatsuki no Yorihime, causes massive damage all over the Moon. Kawashiro Nitori sneaks into the Lunar Capital armoury and helps herself to Lunarian technology.
C3 Consequence: Great Fairy Wars again. The mysterious power of the Moon turns the Strongest even stronger.
Storyline D (Find a way home): The Fairy Team
Route Note: Game begins right on the Lunar Capital. Reisen (II) never made it to Gensokyou.
D1: The Three Mischievous Fairies as the protagonists. Waylays Reisen (II)
D2: Lily White as the protagonist. Ambushes Reisen (II)
D3: Daiyousei as the protagonist. Bumps into Reisen (II)
D1 Consequences: Fairy army wears Lunarian forces down. Watatsuki sisters make peace with the Trio. Some fairies opt to stay, become Moon Fairies.
D2 Consequences: Lunar Capital surrenders as the city becomes a site for botanical outbreaks. Fairies are led home. Some fairies opt to stay, become Moon Fairies.
D3 Consequences: Daiyousei leads the fairies back to Gensokyou through Reisen (II)'s help, leaving the Watatsuki sisters confused when conflicts stop suddenly. Some fairies opt to stay, become Moon Fairies.