^ My right shift is (looks) bigger than your spacebar
I think it's cuz in Japanese, SHIFT isn't a problem because they don't have capitals...
They also DON"T need space bar nearly as much.. because there doesn't need to be spacing between words like ours.
they only need space between punctuation, and new clause.
well, I know they have capital characters, but those are rare, and i've only seen them for numbers.
Many(?) Japanese uses space bar for Kana-Kanji translation.
JIS keyobard has 3 special keys related Japnese input near the space bar, but some Japanese hate these.
Other keys function same with Input Method default settings.
People who hate these special keys(or like long space bar) buy US layout keyboard in Japan.
People used "Kana input" method need Shift key to input small letter.
However, almost Japanese use "Roman letter input" method. So, I think Shift key are not very important for Japanese keyboards.