Side story: Hero's love and Demon king's curse

From my perspective as the narrator, I can tell you that the world we live in is quite different from what it used to be thousands of years ago. In the present day, people generally consider themselves adults once they reach the age of 15, and old once they cross 45 years of age. But it wasn't always like this. The story of this transformation began a long time ago when humans and demons were in a constant state of conflict. Although both sides were equally powerful, they never engaged in a full-fledged war. However, everything changed when the first demon king was born. His innate talent was so powerful that he began to wage war against all other races, including humans. The royal family and the church had to resort to summoning a hero from another world to help them defeat the demon king. But for this, they required a virgin young girl with light magic, which was an extremely rare talent in all countries. Nobody wanted to sacrifice a light magic user who might fail during the ritual (which had a 78.5% chance of failing). However, in the end, the king of the Dharma kingdom's youngest daughter stepped forward and was ready to sacrifice herself. Finally, the ritual was successful and a hero was summoned from a place called 'earth'.

The hero possesses the ability to use every kind of magic, except light magic. On the other hand, the demon king is vulnerable to all forms of magic, but can only be defeated by light magic. Therefore, the hero decides to dispatch a young girl who possesses the ability to use light magic to confront and combat the demon king. This strategy is deemed necessary due to the unique vulnerability of the demon king to light magic, and the hero's inability to use it. By sending the young girl, the hero can exploit the demon king's weakness and increase the likelihood of victory.

From a young girl's perspective, As a young girl, I was overjoyed when I learned that I would be joining a hero on a journey. The prospect of adventure and excitement filled me with eagerness and anticipation. However, I quickly discovered that this journey was not just about battling and defeating demons, but also about confronting and challenging humans who had betrayed humanity. The hero's sense of duty and responsibility weighed heavily on him, and when he was forced to take someone's life for the first time, it deeply affected him. Despite these challenges, I always listened intently as he regaled me with stories about the Earth that seemed like something out of a fairytale. His vivid descriptions and colorful language transported me to a world that was both magical and mysterious, sparking my imagination and filling me with wonder. It has been a decade since we embarked on this journey, and during this time, we have faced numerous life-and-death situations. We have fought against various monsters and demons, but now, we are finally approaching the demon king's castle. As we draw closer to our goal, I can't help but feel a twinge of pain in my heart. The reason for my discomfort is that I have developed feelings for my companion. However, I am only a commoner, and once the demon king is defeated, he is bound to marry royalty. It's a harsh reality that I have to face. I know that I need to find someone to marry, but with the looming threat of this final battle, I fear that I might not make it out alive.

From a normal point of view, the hero stood in front of the demon king's castle, taking in the daunting sight before him. He glanced over at the young girl beside him and mustered up the courage to speak. "I don't know if I can survive this battle," he admitted, "but I want to live a peaceful life with you." The girl looked surprised, tears welling up in her eyes. "Do you mean that?" she asked. The hero nodded, then leaned in to kiss her. As they pulled away, they clasped each other's hands and set off to confront the demon king.

Once inside the demon king's castle, chaos ensued. The hero and the girl fought valiantly, but the demon king was a fierce opponent. In the end, all three combatants were seriously injured, but the demon king was the worst off. Amidst the rubble and destruction, he began to laugh. "You make me think that you are from another world," he said. "I will not kill you out of respect for your will and strength, but you must serve under me." The hero approached the demon king, kneeling before him. But as he did, he plunged his sword into the demon king's heart and shouted, "Eve, use magic!"

The young girl, Eve, began to channel her magic powers. The demon king realized what was happening, but it was too late. "You humans win this battle by tricking me," he said with a sneer. "I, the demon king, curse you that after the age of 30, human males will never have sex with our female partners." The hero and Eve exchanged a look, knowing that they had done what was necessary to defeat their foe. They left the castle, holding hands and looking forward to a peaceful life together, despite the demon king's parting words.

[At that time the hero was 28 years old and normally people (only humans begin) in this world live 90 years]

The people at that time did not understand why the demon king would do this, but within 50 years the human population plummeted to 48%. Human males marry a woman when they are 27. They change the law so that humans can marry when they are 15 and retire when they are 45. Also, this thing affects their life expectancy, which decreases from 60 to 70.

Males have lost their sex drive but women still have it. Therefore, the law gives women the option to marry another man if their husband reaches the age of 30. People don't like this option and it ends.

- To be continued