The title is from the pilot episode of the Sailor Moon English version anime series.
It's really no big surprise to Rachel when she finds out she's the reincarnated warrior Sailor Moon. The talking cat is a bit of a head turner but she's never been one to let the little things stand in her way. She always knew she was made for greatness. The cat — Luna is her name — tells her she needs to find the other Sailor scouts. A mystery and adventure is just what she needs to pull her from her doldrums over Finn dumping her and she applies herself to it with the single-minded focus that she has used for everything she's ever wanted with all her heart. It fills her with such passion she breaks out into song. She is almost certain she sees out of the corner of her eye Luna rolling her eyes at her drama.
Luna tells her that the spell that the Moon Queen cast on the Scouts made it so that they would always reincarnate in the same vicinity and their very natures would lead them to eventually gravitate to each other. The pendant that allows Rachel to transform into the skimpy little outfit that Luna claims is her "uniform," though how she's supposed to fight in this thing without exposing her nether regions to everyone is beyond her, will also reveal to her the other Scouts.
It is of course simple deduction on her part to begin her search among her fellow New Direction members and her endeavors bear quick fruit. Mercedes is the first and is revealed to be Sailor Mars, soldier of fire and passion, which fits Mercedes personality completely. Oddly though, Tina turns out to be Sailor Saturn, soldier of Death and Rebirth, which mystifies Rachel as that doesn't seem to fit Tina at all, but Tina gets a distant look in her eyes and seems to quietly accept her new destiny.
Brittany and Santana are revealed together as Sailor Neptune, soldier of ocean and intuition, and Sailor Uranus, soldier of sky and fury, respectively. The revelation for them is very profound for they seem to remember more of their previous lives than the others. They hug each other for quite awhile and then find a corner in the music room to whisper quietly and hold hands.
The reveal that Lauren is Sailor Jupiter, soldier of lightening and strength, is also a no-brainer but Rachel is starting to think the uniforms need some modern revamps to be more flattering for all body types because seriously, were all their previous incarnations twiggy models or something? But the final straw is when Kurt is revealed to be Sailor Venus , soldier of love and beauty, and he blows a gasket that he has to wear the absolutely "awful, tacky and completely fashion devoid" uniform that he finds himself in. Rachel agrees with him and promises to start looking into some sort of pantsuit ensemble, though secretly she thinks the orange of his dress makes his eyes really pop.
Rachel finds the last sailor completely by accident. Miss Pillsbury calls her to her office because supposedly Rachel has been "acting a bit off lately" and she can always come to Miss Pillsbury to talk if she's feeling more overwhelmed than usually. It's in the middle of this very awkward conversation that Rachel's pendant reveals to the both of them that Miss Pillsbury is Sailor Mercury, soldier of water and wisdom.
After school, Rachel calls the other sailors to the music room and tells them about Miss Pillsbury. Rachel, as their leader, decides that a speech is needed to inspire her troops and of course a song. For once, everyone seems willing to listen to her and they finish with a very wonderful rendition of Brooke Fraser's song, "Saving the World."
Now that the team is together, Rachel looks around for her nemesis. She's almost certain it's Coach Sylvester. It would have to be someone of an evil of mind and a hater of the arts. Someone who opposes love and passion and creativity and Coach Sylvester is the best candidate in her book. So it's a complete surprise that Queen Beryl is no other than Quinn, who quietly plots the Sailors' and New Directions' downfall while being in their midst pretending to be their friends for almost a year before she is shockingly outed by Coach Sylvester.
But in the end, this new adventure turns out to be nothing Rachel expected and everything. The school year flies by. They sing, they fight evil minions, and they fall in love or at least Rachel does. They discover that Finn is the mysterious and dreamy Tuxedo Mask and, even more romantic, her reincarnated lover. Quinn tries everything in her power to win back Finn but to no avail. In the end, true love and well-tailored pantsuits wins the day and they sing Queens' "We Are the Champions" over the burning ruins of the Dark Kingdom.