(AN: I realized CharaTale wasn't a good enough idea on it's own, so I'm replacing it with a suitable replacement; I really hope you guys agree).
It had been a few years after Frisk had freed the monsters from their Underground prison. Things had been going well enough, though it was a rough transition for everyone, both monsters and humans alike. If Frisk hadn't been determined to make peace, it's very likely another war would have started out of fear.
Asgore enlisted Frisk as the ambassador between the two races, and it took all Frisk had to even gain and audience with the leaders of the world. The leaders thought it would be ridicules to listen to a child defending monsters, but after much petitioning and sheer determination, Frisk finally forced the world to listen to them.
The child didn't have much tho say; they ere never really much of a talker, so they kept their speech short. Frisk, broadcasted around the world, spoke a message of peace and cooperation, that if humans wanted to avoid a war, all they had to do was not start one in the first place.
Reactions varied; some humans opened their arms with compassion and welcomed the strange race with open hearts, while others still hated, fueled by ignorance and fear.
Though, if Frisk had to label it, they would say most people shrugged it off, that no one really minded. In the early years, Frisk had worked with the M.A.O.F (Monsters Are Our Friends) to change the neutral and negative opinion. Though, they could never claim to lead the group; no that title belonged to none other than the Great Papyrus.
Most people that talked to him, no matter how strong their fear and hate, always walked away feeling a little bad if they still held on to their negativity. He was always busy, going to cook for homeless shelters, volunteering to help clean up litter off of highways, anything he could do to help anyone in need. Not only that, but he regularly acted as a motivational speaker, inspiring all that listened to his message of digging deeper to reach one's true potential Frisk may have open the door, but many people would say that it was the friendly skeleton that kept those doors open.
Toriel, through the help of Frisk and Papyrus, was able to open her dream school, available for any monster or human child in need of education. Human parents were hesitant at first, but Toriel said they could watch her if they were truly worried. She wanted to show she had nothing to hide, that she honestly wanted to teach children. While the course material was different from human's, and it had to be adjusted for a mixed group, parents would leave the school convinced their children were in good hands. She's now the head of M.A.M.T.A (Monsters and Mankind Teaching Association), a teaching organization in charge of mixed education.
Undyne was regarded as the most dangerous monster, and still is; her hot-temper and fierce loyalty kept her on her feet constantly in the beginning. When she heard of or saw actions against her friends, she swiftly went to her friend;s side, challenging anyone to harm them again. Papyrus constantly insisted he was alright, being very great naturally meant people would resent him, but given enough time, he would open their hears. Asgore took her aside one day, after someone threw rotting fruit at Frisk while they were attending a M.A.O.F rally, before she acted upon her gut instinct. Enraged,, she demanded why he stopped her. He told his ex-guardswoman that the strongest thing she could do is to take it with a smile. That they want her to attack. Afterwards, Undyne became an extremely active partaker in the movement, peacefully solving reaching out, regardless of her temper.
Mettaton became the star he always dreamt of; though people were hesitant to give him a shot, after he blew away other auctioneers, Hollywood had no choice but to accept him for any role he went for. It also helped that he never kept all the money to himself. He constantly gave out his earning to his fans, helping pay for the monster's new homes and supplies until they could find a source of income. Frisk the them didn't see him too much, but he always sent them a letter every week, to keep him humble, he said. He didn't want to forget the people that got him to where he was.
Alphys was the most quiet of the monsters, keeping to herself. She mostly followed Undyne around, until she was allowed a lab on the surface. Afterwards, she years actively trying to cure the Amalgams, though she did work on other projects as well. She studied how the different monsters would react to certain surface environments, suggesting specific locations and human-food substitutes for the time being. Currently, she's working on a medical project; seeing how to unlock the determination in monsters without losing their physical property. She believes that if she could, it would increase monster's immune systems and extend heir natural lives. Though, she hasn't given it too much work though; she was still too worried from her previous experiments. Plus, it was more enjoyable hanging out with Undyne. Needless to say, the two of them now shared a domestic life.
Asgore, obviously, lead the monsters, making agreements for various of monsters to live where they would be most comfortable. Frisk had to speak for him at frst, but over time, Asgore was able to go to meetings without the child. Leaders began to respect him for his negotiation skills, how even in the face of rejection, he found a way to compromise for both parties. It was a struggle to earn their trust, but Asgore was patient. He knew it would take time, so when he was met with fear and prejudice, he welcomed it with a smile and understanding.
Sans... Well, Sans just runs a hot-dog stand a block down from his and Papyrus' new house. But he made people laugh, so there's that.
Through hard work and love, Frisk had made sure everything worked out, and they knew they had gotten the happy ending they had hoped for. It had taken years, but they had achieved their goal. The game was over. They lived a happy, peaceful life with Toriel. They went to school, they had a family, they saved both races. It was finally done.
At least, it was.