Luochuan woke up and came to the world of Demon Slayer. He and Zenitsu were picked up and raised by the Sound Pillar Jigoro Kuwashima. However, he did not have the talent to practice breathing techniques, so he could only accompany Zenitsu to learn Thunder Breathing. Just when Luochuan was thinking about how to survive in this world full of demons, Luochuan awakened the friend system! As long as you become friends with each other, even verbally, you can get various rewards! Add Zenitsu as a friend and get the reward of Thunder Breathing Type 1·Thunderbolt Flash! Add Tanjiro Kamado as a friend and get the reward of "Gap Thread"! Add Lower String Five Rui as a friend and get the reward of Blood Demon Jutsu Engraving Rotation! Add Flame Pillar as a friend and get the reward of Flame Breathing Secret·Ninth Type·Purgatory! …….. "No, you are full of blood demon jutsu, you say you are a pillar?"