3 Life is Roblox

Time passed quickly, and Giyu was now five years old. With the memories of his past life, he understood that a true miracle had occurred—somehow, he had been sent back in time. The joy he felt was beyond words. He could spend time with his family again, something he had never thought would happen. But more importantly, he wouldn't be a coward this time, letting others save him. This miracle shouldn't be wasted. He was determined to make full use of it and be the one to protect others now.

In his previous life, when he was eight years old, his parents had died from an illness. At thirteen, his sister was killed by a demon, and Sabito lost his life in the same year. By the age of nineteen, Tanjiro's family was slaughtered by a demon, with Nezuko turning into one herself. Giyu resolved to do everything in his power to change these tragic events.

"Giyu, what are you thinking about so deeply?" Tsutako, Giyu's older sister, asked as she found him looking at the sky, lying under a tree in their backyard. Giyu had a habit of hiding from his family, preferring to sit alone, especially when visitors were around. Over the years, Tsutako had memorized all the places where little Giyu might hide, so it was only a matter of time before she found him.

"Put me down, Tsutako" Giyu said in his usual emotionless voice, but Tsutako only smiled, picking him up and carried him toward the house.

"Giyu, you have to meet my fiancé. He'll be part of our family, so it would be great if you two became friends."

Giyu's face remained blank. He knew who her fiance was—a boy around her age, the only child of a successful blacksmith family. Giyu had met him in his previous life, though he didn't remember much about him or his family. What he did remember was that the boy wasn't bad, and the two families had been friends for years. The marriage had been arranged long ago, more a promise between families than anything else.

Giyu had no particular feelings about it. If Tsutako didn't want to marry, they could break the engagement anytime. But in a way, Giyu was grateful. He already planned to leave when he was thirteen to become a demon slayer, so he could leave more easily knowing his sister was taken care of.

As a hashira, he couldn't stand by while demons roamed the earth, so the decision to leave at thirteen was not something that could be changed. He would have left earlier if not for wanting to get rid of the demon that killed his sister.

He was already ready to continue his job as a demon slayer with his body being physically stronger than the one he had at this age in his past life. He didn't exactly know how, but everything became easier, as he started secretly training using a stick as a sword he could feel himself improving fast, to fast for his comfort.

He could only speculate it was due to him picking up an weapon after not doing so in years, last time being in the life and death battle with the demons, maybe that experience allowed him to grow even further but he never realized it due to not having to rise a sword again.

Another one of his speculations was that he was stronger due to the mark appearing so early and his body slowly adapting to it, but he still wasn't sure about that theory, for all he knew it could be a combination of the two. So in the end, he decided to accept it as a gift form the gods and train in silence 

Waking up from his daydreaming, Giyu and Tsutako entered the room hand in hand, Giyu saw three new faces alongside those of his parents: two adults, a man, a woman, and a young boy.

"What a cute little child," the woman said, to which the man added, "The boy sure has your face, Tokito. I'm sure he'll be a great successor to your business."

(Author note: The man referred to as Tokito is Giyu's father, and Sarui is his mother. I couldn't find their actual names anywhere, so I'll do it myself.)

After speaking, the two adults encouraged their child to step forward. The boy approached Giyu and Tsutako, holding a small box in his hands.

"Nice to meet you, Giyu. I hope we can become friends. This is for you," the boy said as he handed Giyu the small gift, earning a gentle, satisfied smile from Tsutako.

Giyu stared at the box for a moment, making the boy sweat a little before he finally accepted it with a quiet "thank you."

---

A few hours later, the visitors left, leaving Giyu alone with his family. Tokito and Sarui noticed Giyu staring at them intently, but this time was different.

'I can see it,' Giyu thought. After years of practice and intense focus, Giyu finally had access to the Transparent World, a powerful ability that allowed him to see through the physical body of any creature. The world became gray as Giyu could see every muscular contraction and joint movement, as well as the flow of blood. This ability wasn't just a tool for the future; it was something that could help him now. As he observed his parents, he watched their lungs' movements, and he saw it—a strange glow deep within both of their lungs.

(Author note: I am not a medic or know a lot about health stuff, so please imagine it as a fictional illness)

"Father, Mother, we should visit a doctor," Giyu said quietly, to which his parents began to sweat buckets of water.

Over the past few years, Giyu had often stared at his parents, almost as if trying to see inside their bodies. Sometimes, he focused so intensely that the mark on his cheek would appear, leaving his parents worried. A year ago, he had suddenly suggested they visit a doctor. They had been reluctant at first, but when Giyu threatened not to go himself if they didn't, they eventually agreed. Although Giyu knew what the Slayer Mark was, his parents did not. They often took him to doctors to check on him, but more often than not, their questions went unanswered.

Giyu felt bad for wasting their efforts, but he couldn't tell them the truth—that the mark was a curse that granted power in exchange for death at the age of twenty-five. He didn't want to make them sad, so he decided to keep it a secret.