Demon Slayer: Kimetsu no Yaiba

After reading the Demon Slayer manga from the current world, since you've transmigrated to this world, you want to change the fate of others so that everyone won't feel pain, and protect their most important family members. As for the time you returned to, it's before Kanae Kocho dies. That is, when Kanae Tsuyuri has just become a Hashira, you want to help her as much as possible, so that she won't die. And you also need to untangle the emotional knots of others.