Kaze Hikaru is currently published in a monthly magazine called Flowers by Shogakukan.
So far, 24 tankobans have been released.
Each volume contains approximately 5 chapters, and an extra section at the end. The extras are very enlightening showing bits of Watanabe-sensei's extensive research.
English - "Kaze Hikaru" under Viz's Shojo Beat
Chinese - "Œõ”V•—"
Vietnamese - "Kaze Hikaru"
Indonesian - "Flash of Wind"
Korean - "baram ui vit (??? ?)"
If you could supply me with information regarding other language releases of Kaze Hikaru (ISBN, Publisher, Title in said language) I will be extremely grateful!