Many thanks to Ayako for the link!
In an exclusive interview with Helen Earnshaw for Female FIrst, Penny Rose spent the first art of the interview discussing the costumes for 47 Ronin. When asked how hands on Keanu Reeves was when it came to the development of his costume, Ms. Rose said:
He was really interested. His mother was actually a seamstress and a tailor, and so he knew quite a bit about it.
The problem was, he was playing this peasant and so I could never really jazz him up much. Once we had decided on the peasant’s look, he was terrific.
You can read the entire interview here.