Once in day, many people are died due to the cause of demons.There are many kinds of demon. Some where STRONG

And some where weak

The cases where running and started the #manga#anime#series

Once the day The family of the demon slayer were living happily. The demon slayer go out to find some wood to make fire. When he was coming from the forest to home He saw his family where killed by the (MOST POWERFULL DEMON).

But he knew that his sister is still alive who was a demon. The demon slayer carry his sister and run to hpspital for her sister suddenly on Of the demon slayer came amd fight with other demon slayer because his sister was demon. And the demon slayer work to kill the demon.