Kyojuro needed a place to stay the night after one of his missions, and he knew he couldn't just go back to his home with Senjuro and his father. His father would probably just kick him out, and tell him how he's never home and that being a Hashira is useless.
So, he came to you. His good friend. He knocked on your door at around 2 AM. You just happened to be awake, and you got up, looking out the window first. There, Kyojuro stood, at the doorway, covered in snow. His hair was adorned with snowflakes. So, you brought him inside, and gave him a new pair of clothes to sleep in for the night, and brought him to the guest room.
The next morning, Kyojuro wasn't feeling well. You had gone to wake him up to tell him that breakfast was ready. You made extra, because of his big appetite.
"I'm not hungry," He replied.
As soon as he said those words, you knew something was up. He never turns down a meal.
You opened the bedroom door, and you saw him, lying on the futon, his shirt off completely as his skin was flushed, and he was sweating.
"Don't come in here.. I think I have a fever. I don't want you to get it." Kyojuro said groggily.