Ichijoji, Chris Hellman (author of The Samurai Mind) has a story about Hirayama Shiryu. Below is an excerpt. The full post may be read here.
Another story that well illustrates his character is an episode that occurred with one of his friends, Shimizu Akagi, who was obviously of a similar mind to Hirayama. Walking home one cold evening in winter, Shimizu remarked "The heroes of old used to fight in the middle of winter. If we are serious about our martial studies, shouldn't we prepare ourselves for the same. How about a little swim?"
Hirayama, of course, agreed, so they both got into the icy water.
After finishing their swim and getting out, Hirayama proposed a nice bowl of hot noodles, to which his friend replied "Gotcha! They wouldn't have had that kind of luxury on the battlefield!"
Hirayama conceded the point, and they both went their separate ways home.
However, Hirayama's friend, on his way back, figuring Hirayama would go back home and be snuggled up warm in bed, thought he would surprise him and score double points. When he got to Hiryama's place, he was not in bed, but sitting on his normal oak board (which he used in place of a cushion), studying, according to his normal schedule. (In fact, he usually slept on the floor of his dojo rather than in a futon, with only a light cover, so I doubt he would have been getting very warm in any case).