You Don't know Us; "Don't assume things, the same with people.." This is the third book of the series. Please read the first two books to understand. (Y/N) Kibutsuji and (B/n) Kibutsuji have brought back Muzan from the dead, along with all the others of the demon slayer crops that they turned into half demons. But multiple demons have gotten out of Muzan's control. The Demon Era hasn't ended but the war has. A new Era starts to rise. The Era Of Quirks. Normal humans having supernatural abilities. The Demon Slayers And Demons still trying to hunt down the loose demons at night, but working and teaching as a pro hero at day. Rui Kibutsuji, the youngest of the family now is in UA High. How will he's journey go?