I didn't stay too true to the game's original lore/story (although I didn't stray too far either). Think of it as an alternate time line if you will.
I also misspelled Patchouli Knowledge's name wrong, kill me.
In Marisa's life, there were only two people that mattered. Those people were Alice Margatroid, and Patchachuli Knowledge. Those two people were all Marisa ever thought about. Those two people were her best of friends. Those two people were Marisa's life line. Those two people were the only people Marisa had ever loved.
The only problem was the "two" in "those two people".
Love is a double edged sword. It will give you some of the happiest moments in your life. Love will take you to worlds your heart never thought existed. Love will give you people who you would have no problem spending the rest of your life with. On the other hand, love will also be your down fall. It will make you do things which you would never do otherwise. It will completely and utterly destroy someone without any mercy if they let it. To many people, love is the only reason why they exist. To many others, love is the bane of human existence.
Marisa had been in both of those groups.
Marisa had known Alice her entire life. The two were some of the only people living in the Magic Forest, on the outskirts of Gensokyo, which meant they spent a lot of time together. Ever since Marisa was little she went to Alice's house. They would play together deep into the late night hours. Many a night they fell asleep next to each other, worn out from a day long play session. Alice was always there for Marisa, and Marisa was always there for Alice.
Marisa first felt feelings for Alice around the time both of their parents were killed by the vampire Flandre Scarlet.
She was only a little girl when it happened, so she had to rely on what others told her to peice together what happened on that fateful day.
You see, Flandre was deemed far too powerful to be let out onto the world just a few months after she was born. She could, and did, destroy any opponent that faced her. She would use spell cards that were unknown, unheard of, and unpracticed. Even the most advanced magicians in Gensoyoko, people who had dedicated their entire lives (which often times was hundreds of years long) to magic, couldn't replicate or dodge, her attacks. She was considered a god by many, and was commonly believed to be unstoppable. All the while she was less then seven months old.
It was because of this incredible strength that her sister Remilia Scarlet locked her away forever in the basement of the Scarlet Devil Mansion. In this basement she was locked away for what should have been the rest of eternity.
However, due to unknown circumstances this was not the case.
After about six centuries of being locked away from the world, she broke loose and turned all of Gensokyo into Hell on Earth. The death toll was already climbing into the hundreds after the first hour. It was clear that all of Gensokyo would be wiped from the pages of existence if something was not done to stop the vampire. In order to stop Flandre from destroying their homes, the most advanced magicians and Youkai from the city desperately banded together. This band of magicians was Gensokyo's last hope.
Alice and Marisa's parents were in this band.
There is a spell card which is nameless. It is often referred to in local legends as a spell card that could kill the very gods themselves. This spell had enough power to stop time and split every atom in the universe over a thousand times. If the band of magician's and Youkai were to use this spell, it would be the first time outside of legend that it would be activated.
The group of magicians and Youkai could just barely muster the power needed to use this spell. It took all of their strength and concentration, but they were able to pull it off. They defeated Flandre, and she was banished again to the basement of The Scarlet Devil Mansion. However, all the power that was needed to use the spell came from the magicians and Youkai's bodies, which didn't leave them enough power to maintain bodily functions. All of them died.
All of this happened when Marisa and Alice were only small girls.
They were traumatized. Without parents to look after them, the two spent all the time they could together. They were, for all intents and purposes, sisters. They would rely on each other to have a shoulder that they could cry on after the incident. Naturally, this only cemented their friendship. Alice was the first one to admit her love to Marisa. When Marisa said that she felt the same way, the two finally declared themselves a couple.
Then came Patch.
Marisa had known Patch for a while, they met after the Scarlet incident when Marisa was going to visit her parent's graves (which were located in front of the Scarlet Devil Mansion). Patch was sitting there, enjoying one of the only days which she wasn't bed ridden. The two found that they shared many interests, including magic. While they did talk from time to time, Marisa didn't fall in love with Patch until her teenage years.
Patchachuli had one of the largest libraries in the known world. Since only a few people knew about it, it was often empty. Marisa, on an almost weekly basis, would go and borrow some books. While the books were a big help to Marisa when she started studying magic, one of the only reasons she went there was to talk and read to/with Patch.
Marisa didn't know what made her fall in love. Her love just hit her while she reading to Patch on a day where she was too weak to even pick up a book, let alone read and concentrate on one. The story Marisa was reading to her was a love story. The story was quiet cliche. It was about a Prince who wouldn't age until he fell in love or something along those lines. While reading, Marisa remembered looking down at Patch laying in the bed, looking up at her through her purple hair. She just looked so small and frail, and like she needed protection. Maybe it was Marisa's motherly instinct, but from that day on Marisa just couldn't help but love her. The fact that Marisa and Patch lost their virginity to each other didn't do anything but increase their affection.
At first, loving both Alice and Patch was quiet awkward for Marisa. She knew she shouldn't love two different people, she knew that sheshouldn't be able to love two people. However, her thoughts didn't change the fact. She was still madly in love with both of them. So, she figured that the best solution to her problem was to publicly have a relationship with Alice, and have an affair with Patch on the side.
It was the perfect plan. Patch didn't leave the Mansion much, and no one knew that the two even knew each other. It was almost guaranteed that Patch wouldn't know about Marisa's relationship with Alice and since Marisa was already going to Patch's library on a regular basis anyway, Alice wouldn't suspect a thing.
Marisa pulled it off for a few years surprisingly. She would live with Alice, and every Friday she would go to Patch's library and give her the needed attention there. Whenever Patch asked why Marisa wouldn't move in, or at the very least come and visit more often Marisa stated that she had to hold down a job which took up most of her time during the week, and that moving into the Mansion would make it next to impossible to get to work. While Marisa felt bad about lying through her teeth, it was the only thing she could do to make everything work.
Everything was just perfect. Patch was clueless. Alice was clueless. Everything was going just fine until Patch's immune system woke up from it's years long rest.