Ranma's life had definitively taken an unexpected turn. He still remember the day that changed everything like it was yesterday.
Only a few weeks after the failed wedding, not only Akane had finally calmed down, but he had also gotten enough time to gather his courage and finally say loud and clear his feelings. He probably would have chickened out, like always back then, but he will never be sure, since as soon as he entered Akane's room (with her permission, of course) a strange woman teleported in, someone in their arms, claiming "Saotome Ranma, the world need your help. The kind that mean a great sacrifice from you."
The woman had long dark-green hairs, a skin a bit darker than usual in this part of the world, and wore what he saw as a perverted version of a seifuku. "You're one of the Sailor Senshi…" interrupted Akane, in awe. "…But I don't remember hearing of one looking like you."
"I wasn't needed until now." Simply answered the Senshi. While she seemed impassible to her two interlocutors, Pluto was inwardly distressed. Amy wasn't supposed to end up mortally wounded, especially not so soon after awakening to her destiny and powers. But she couldn't let her emotions cloud her judgment. To survive, the world needed a Sailor Mercury, she'll have all the time later to see if Crystal Tokyo was still a possible future.
"While you don't look the part, because of how your father raised you, you are a genius Ranma" affirmed Setsuna, not saying anything about how shameful it was his old man made sure Ranma would develop mental blocks preventing him to use his brain for anything not related to the arts. "Just like this dying girl. She's Mizuno Ami, also known as Sailor Mercury. I can't save Ami, and without a Mercury, without a full team of Senshi, the world is condemned. But maybe, if we merge her and someone similarly intelligent, Mercury can survive Ami."
Ranma was about to scream something along the line of "but I'm a man", Pluto never let him the time. "The choice is simple, Ranma. You can either renounce being a 'man among men' and help save the world, or you can refuse to become one with Ami and let everyone die."
The sex-changing martial artist only needed to think a few seconds before accepting. After all, a martial artist duty was to protect those who can't protect themselves. For answer, he simply nodded. "What I do?"
"I need you in female form, lying down. I would recommend a soft surface, like your fiancé's bed."
It didn't take long for Ranma to fetch some cold water and do as he was told. He didn't know back then how the strange woman knew his name, let alone his curse, but he could feel her desperation. That, and even him had heard of the 'Warrior Sushi' or whatever.
Setsuna somehow found a way to compress all of the dying Ami into her star-seed, something that still puzzle Ranma to this day since it's clearly not a part of Pluto's powers, and forcefully implanted it in Ranma's soul, forcing the two to merge together. To Akane, still present, it seemed to be quite taxing on the green-haired woman, and quite painful for Ranma.
As the fusion progressed, Ranma's feminine form slowly shifted, turning into a perfect copy of Ami. Something not even Pluto expected.
Akane watched the girl with lighter blue hairs open her eyes and slowly sitting up. Worried, she immediately asked "Ranma? Are you alright?" while at the same time Pluto questioned "How do you feel Miss Mizuno?" The way Pluto addressed the girl didn't go unnoticed by Akane, making he heart sink. The baka she loved so much wasn't anymore.
For her part, said girl on the bed simply closed her eyes and concentrated. There was so much she didn't understand as Ranma she did now, and so much she never suspected as Ami… But there was more pressing maters than her impeding identity crisis.
Thanks to Ranma's training, she could not only feel the huge amount of ki inherited from him, but also her magic, along with the magic of the curse. "I still have the curse?!" she thought "And my powers are water based. Maybe…"
Neither Akane nor Setsuna could believe what they were saying. The person in front of them was shifting from Ami to male-Ranma and back again.
The person in front of them finally settled on their Ranma form. "Well, that's one way to broaden your horizon." He was, naturally, speaking of how he was free of any mental block, able to study anything he want rather than being limited to the art. Sensing how Pluto was worried he looked at her and said "Don't worry, I will help as Sailor Mercury, but I need a little chat with Akane first." Under his breath he added "I hope I'll be easier now." Not that the girls couldn't hear him, since they were just next to him.
"Akane, I…" he took a breath, "I loved you for quite some time but, between my shyness and all the nonsense Genma pounded into my brain, I systematically ended up insulting you instead of telling you how I felt. For that I'm sorry. Know that even after merging with someone-else, I still love you from all my heart." On those words, he passionately kissed Akane, who felt him shift back into Ami toward the end of the kiss. The other blue-haired girl looked her in the eyes, her gaze full of the love she inherited from Ranma, tears staining her face. "I hope you will still be part of my life. If not as lover, then at least as a friend." She then took a paper from Akane's desk and wrote her name, (水野 亜美, which mean Mizuno Ami) her address and even her phone number.
She then used her transformation pen and softly said (instead of streaming it, like usual) "Mercury Power, Make Up". In a flash, she became Sailor Mercury in front of Akane. "Do you have enough juice left to port us bact to Minato, Pluto?"
Ranma chucked, remembering that not only had he (or rather she) had transformed for nothing since by the time they were back to Azabu-Juban, the girls had ended the fight. And then he had to explain to his mom, Saeko Mizuno, why he was wearing his usual red Chinese silk shirt and black silk pants. He hatted lying to Saeko, who was a far better mother than Genma ever was a father, but he was already walking a fine-line with the other Senshi with Akane knowing the truth. (And they hated him enough with the 'training from hell' he insisted upon, even though it greatly helped them later on.)
His former fiancé had accepted to keep being part of his life. Officially, they had claimed Ranma had scarified his life to save Ami, Akane keeping in touch to make sure the girl was alright and, eventually, became her friend. It was quite strange for Akane, that person she called a friend, (and would eventually come to call her lover) wasn't Ranma but, at the same time, it was clear he was in there somewhere.
But becoming one with Ami, becoming a far greater Sailor Mercury than either of his identity could have before merging, was only the first step toward his new life. The second one had been forced upon Akane by Shampoo.
The purple-haired amazon had somehow gotten into her head that Ranma was still alive, (technically true but back then Ami hadn't changed back into Ranma since she left the Tendo compound) and that Ami and Akane were helping him stay hidden. Because none of the blue-haired girls accepted to reveal where Ranma was hiding, she showed up with an artifact able to transfer a curse from one people to another, and used it on herself and Akane, who she then locked in cat-form.
As soon as she had learned of Akane's disappearance, Ami had changed into Sailor Mercury and searched for her, but she found her just as the got locked, to late to prevent it.
While not as scared as Ranma would have been, it was clear to Shampoo that this Mercury warrior was suffering ailurophobia.
While Akane's new form was terrifying to Ami, even if Luna and Artemis had helped her get better when confronted with the furred demons known as cats, she also knew that she was still Akane on the inside. And Ami couldn't stand to live without Akane by her side, she would rather go back to the pit of starving cat. As a result, she decided to slowly go near neko-Akane and take her in her arms, the first time she touched a cat since her fusion with Ranma.
Shampoo could hear the strange girl muttering Akane's name. She could also see the tears flowing freely, some even falling on the girl-turned-cat, causing a strange symbol to glow on it's forehead. If Ami or Akane had seen it, they would have recognized it as Mercury's sign. What happened was that, since she still was in her Sailor Mercury form, her tears were magically charged. Said magic interacted with the curse altering it, turning Akane into something similar to a Mau, like Luna and Artemis. It also broke the lock on the curse, but that's something they wouldn't learn until far latter.
Having Akane in the form of a cat would do wonder to help cure Ami of her ailurophobia, with the added bonus of letting her turn the neko-ken from a problematic mental state to an actual martial art, one you could even teach to a sufficiently intelligent cat.
Ranma got pulled out of his reminiscing by an announcement that Queen Serenity had come to visit the newly restored planet Mercury. "That's just like Usagi, coming during my date with Akane…" he internally lamented. But making his queen wait wouldn't do, even if said queen was also his friend. Turning back into Ami so he could change into Eternal Sailor Mercury.
As soon as she said her transformation phrase, she heard her wife childishly say "Last one to the dock is a rotten egg!" before taking on her four legged form and running ahead. Ami knew that, even with the boost provided by her Eternal form, she wouldn't be able to catch-up to a cat practicing martial arts, especially not one she had given the Kachū Tenshin Amaguriken training, but still decided to run after her, just for the fun of it.