Demon Slayer: the Beginning of Hot Weapons

[Time travel, single male protagonist, single female protagonist, no system, more realistic] In the early 20th century, during the Taisho period in Japan, there were rumors of ghosts that ate people after sunset, terrifying evil spirits, and mysterious ghost hunting organizations. Lan Xu, a time traveler whose body and soul are somewhat separated, has no system and only vague memories. It seems that in the future, cold weapons will be completely eliminated? How is it possible? How can such a fancy little toy compete with an exquisite sword...