“She's the shrine maiden who goes around killing people.”
Reimu "Bukkake" Hakurei is the immortal shrine maiden residing at the Hakurei Shrine, a financially suffering, godless, and pointless Shinto shrine in Gensokyo, a village filled with magical little girls. Her interests include: strange sexual fetishes, fake Shintoism, genocide, Sean Bean, BDSM, live action role-playing, and axillas.
Born in the Gerudo Desert, Reimu spent most of her early life gardening and shaving her unsightly armpits. After struggling to find friends, she left home to find someone who would not judge her by body hair. The journey brought her to Gensokyo with its entirely female population. She knew this would be her home, as women never criticize one another, least of all about appearance. There she met Marisa Kirisame, a kleptomaniac witch. As they were both social outcasts, Reimu and Marisa quickly became friends.
One day, while reading a book that Marisa had stolen from some pajama-wearing librarian, Reimu discovered that a remedy for unsightly armpit hair was hidden in the mountains above the Hakurei Shrine. She immediately set off to find the potion, but was defeated by various monsters, demons, angels, elves, unicorns, and succubi--collectively simply referred to as youkai--and returned to the shrine in shame. She was moping about when she found a magical, off-color yin-yang orb. She used it like a kickball to kill the youkai and thereby ascended the mountain.
After finding an entrance to the demon world in a cave, Reimu defeated the Archangel Sariel using only the ball and a stick. After the walk-off play, she triumphantly shouted, "Let's play two!" Eventually, Reimu found a direct route to Hell (of all places). Curious, she descended into Hell and fought a master swordsman named Konngara. Reimu again prevailed by momentarily shocking her opponent with her armpit hair.
Reimu gets wheels
After her exploits in Hell, Reimu continued her search for the armpit-hair remedy in the surrounding forests and mountains of Gensokyo--after a brief vacation in Hawaii, where she captured a giant turtle named Genji and started testing drugs on him. One side-effect of the drugs enabled Genji to fly. The reader has surely sampled comparable drugs. Now Reimu had a neat new vehicle.
One day, Reimu encountered Marisa, feeling neglected, and gratuitously attacked her before returning to her search. But she failed again to locate the potion and returned to the shrine, only to find that a ghost, Mima, had taken up residence in it. Reimu battled her and lost miserably (odd, as she had just beat an archangel and a master swordsman with only a stick and a ball). But Reimu let the phantom stay in the guest room, as long as she didn't wreck the place.
A month later, Reimu was on one of her incessant searches when she came upon some magical ruins. At the gates, a crowd had gathered: Marisa, Mima and several other cameo actors. Reimu fought her way to the center of the ruins, which were now revealed to be a spaceship. Its pilots congratulated Reimu on her skills and offered to take her to a perfect world where even a girl with copious body hair would be accepted. Reimu, of course, replied by killing them, bringing to an end an era of interstellar peace.
So countless youkai began attacking the Hakurei Shrine for no obvious reason. Perhaps it was driving down property values. Reimu and Marisa separately went to investigate in the mountains, because that's where everything is, in the mountains. The girls murdered an innocent youkai named Orange and eventually came upon a lake of blood with a mansion on an island. Any time you see a sight like that, you just know you're welcome, so the two walked right in. But surprisingly, the two were attacked by many guards, including a scythe-wielding demon called Elly.
As the girls made their way to the center of the mansion, they came upon a sleeping youkai with the fitting name of Yuka. Yuka was having a nice dream and was angry that she was awoken. In retaliation, she tried to destroy the world with her awesome Master Spark. Luckily for the world, Reimu stopped Yuka and Marisa stole her Master Spark power for her own. Reimu was miffed that this place didn't have the armpit-hair remedy either.
An appeal to heaven
Later, Gensokyo was beset by more demons, this time from the demon world of Makai that Reimu entered when first searching for the remedy. Reimu was annoyed by the demons and traveled to Makai. She found it in a chaotic state and eventually reached the dark castle of Pandemonium. Here she met Shinki, the Goddess and creator of the once-peaceful Makai. She revealed to Reimu that when Reimu previously came down to Makai and defeated the archangel Sariel, the kind and loving ruler of Makai, she created an unimaginable amount of chaos that eventually leaked out and attacked Gensokyo, meaning that Reimu had caused the sufferings of hundreds of thousands of demons and youkai. Reimu made sure this secret was safe by killing Shinki and burning down Makai to stop the demons. Reimu returned to the surface as a hero for stopping the demons and was finally accepted by the people of Gensokyo for who she is.
One cold day in winter when Reimu was feeling particularly hungry, she took Genjii and made him into turtle soup.
Reimu continued searching for the remedy for hirsutism through the next summer, when a strange, scarlet mist started to cover the land. This bothered the residents of Gensokyo, but they just sat there and complained, until the mist became so thick that it blocked out the sun, causing crop failures and sinus conditions.
Reimu's monotonous search for the potion was impeded by the thick fog. She tried to kill it, as this is her basic response to anything. After this failed, she returned to the Shrine to recruit Marisa to find and destroy the source of the fog. Unsurprisingly, Marisa and Reimu got separated in the fog. Reimu went on a forested route while Marisa ended up on a path to a lake.
The forest became increasingly dark and spooky. While wandering aimlessly, Reimu came upon a youkai of darkness named Rumia. (Reimu, Rumia; Rumia, Reimu.) Reimu attacked Rumia with a key weapon, one-line insults, and a fight ensued, Reimu using danmaku, a new Bullet Hell with overly complicated shooters, and Rumia using darkness. Rumia attempted to blend in by covering herself in a shield of magic darkness, but it not only failed to cloak her but blinded her. She ended up crashing headfirst into a tree and knocking herself out, rendering Reimu the winner.