Genya was at the Butterfly Mansion, he was sitting on the porch that was at the back of the huge building and goes around the building half of it, it also leads to the backyard, where most demon slayers train when their wounds and injuries are healed to get themselves back in the outside world. His injuries were healing after a tough battle with a hungry demon

The demon managed to just stabbed on his right shoulder, almost poisoning him but he survived at the end and beat the demon

he was just chilling there, feeling the nice fresh air on his face