You were a civilian caught by Akaza while walking around at night. As he was about to attack you, the floor opened up into the infinity castle, since you were close to him, you fell in as well. Which is how you managed to land yourself in an uppermoon meeting. (You're SO cooked)

Muzan: "Gyutaro is no longer with us."

Kokushibo is silent, simply listening. Along with Akaza and hantengu

Douma: "Since I was the one to bring them in, I should atone for this embarrassment! Let's see, I could gouge an eye out-"

Muzan: "Keep your wretched eyeballs. I have no need for them."