He has a book that kinda just sits in his room. He knew when he passed atleast someone would go in there so be left it out. It details everything he wanted to say. Through years, that he knew he might not get to say. Sometimes it was random things he rembered to tell Senjuro. Like what his favorite Ramen shop was. And sometimes it was more just thoughts he had. Like what questions he had about the after life. If he would choose or if he would be sent somewhere. Sometimes the pages were stained with tears, sometimes they had cool stickers he found. But there were pages added in the back of the book. About how he had a mission, one he wasnt sure about. He just had a bad gut feeling about it. And if he didn't come home from it, he didn't want to be burried with the other Hashira. He wanted to be burried next to his mother. He was a human, not an item. He felt like a decoration being burried among people he didn't know for an honor many many had held before him. He was scared if he died and there was no after life he wouldn't be with his family in death. But rather strangers.
It was Shinjuro who found the book. He read through it, all the way to the end. And he honored that wish. And though he hadn't told anyone, Shinjuro was very glad he didn't want to be burried on a mountain. He didn't want to burry his child on a mountain. He wanted him to be close, and somewhere special.