Where to buy ebooks written in japanese

where to buy books written in japanese. and can i import them here?

青空文庫というのがあります。
http://www.aozora.gr.jp/index_pages/person_all.html

ミス・マーサ・ミーチャムは、街角の小さなパン屋をやっている。とんとんとんと、階段を三段上がって扉を開けると、ベルがちりんちりんと鳴る、そんな店だ。 ミス・マーサは四十歳で、通帳には二千ドルの預金があり、差し歯を二つと、いわゆる同情心を持ち合わせていた。もっと結婚運に恵まれない女性でさえ結婚していく中で、彼女はずっと独身でいた。 http://yuji.cosmoshouse.com/works/loaves/loaves.htm

“Miss Martha Meacham kept the little bakery on the corner (the one where you go up three steps, and the bell tinkles when you open the door).
Miss Martha was forty, her bank-book showed a credit of two thousand dollars, and she possessed two false teeth and a sympathetic heart. Many people have married whose chances to do so were much inferior to Miss Martha’s.”

i dont know how to use it its too complicated