Naginata Style (薙刀式), by author Toshihiko Ōoka (大岡俊彦), is a Japanese kana-based keyboard layout which caught my interest. It was developed to work on traditional keyboards with spacebar used as central shift, but also works well on small ergonomic keyboards with thumbs-keys. The most common kana are a single key press, but generalising the idea of shift keys any other kana requiries a two-key combo (including compounds like "きゃ" or "kya"), or at most a three key combo (compounds like "ぎゃ" or "gya" with a ten-ten modifier). The layout is more ergonomic than Qwerty and the rarely used JIS Kana layout, and needs less key presses than romaji.
