The protagonist finds himself unexpectedly transmigrated into the Demon Slayer universe due to unknown reason, shrouded in mystery. Thrust into this familiar yet foreign world, he determined to enjoy all the things this world could offer and uncover its secret. No matter what, he promised to himself to seize this unexpected opportunity. This time, perhaps—just perhaps—he might be able to truly grasp and understand the essence of living, something he failed to have in his past life. Not afraid and care what kind of challenges and obstacles he will face in the future, he will make sure this life will be different to live a life free from the weight of past regrets. What to expect: 1. Smart MC. 2. Lots of training, be it physical and emotional. 3. MC taking advantage of the plot he knew and remember. 4. There's going to be a lot of original arcs. 5. The original Demon Slayer plot will "mostly" stay the same. Disclaimer: I don't own Demon Slayer or it's characters (except the original characters I created).  Warning: 1. The MC won't be op from the get go. In the beginning of the story, it will be mostly focus on the world building and understanding of his character. He will undoubtedly grown to be strong, but his power would be gained via hard work for quite a long time. 2. Probably no romance (I can changed my mind later but for now I won't focus on this aspect). 4. The story will start slow, a few of initial chapters will be around MC trying to familiarize himself into the world and well, trying not to having an existential crisis—instead of immediately training to become a Demon Slayer. 5. Lastly, The MC of this story won't put his life at risk unless there is no other choice left.