Hope this list will be useful in your search of new Boston Pops re-releases in Japan (some in limited quantities). Use the research field and just writing John Williams you'll get more than four hundred references (don't forget also exists a guitarrist called JW and a piano jazz player), most of them are showing picture and english description, but you'll find some in japanese characters and no picture, after requesting Amazon Jp a translate from japanese into english, hope you can know what the heck you're ordering hehehehehe... enjoy them!!!
These leinks belong to Amazon japan , also you can find some references at CdJapan
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Pops in screen (ポップス・イン・スクリーン)
ASIN: B00005FFL4
http://www.amazon.co.jp/exec/obidos/ASIN/B00005FFL4/
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Star wars "Return of the Jedi" (スター・ウォーズ
「ジェダイの復讐」) ASIN:
B00005FFL5
http://www.amazon.co.jp/exec/obidos/ASIN/B00005FFL5/
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Pops on stage-Cats (ポップス・オン・ステージ
~キャッツ) ASIN: B00005FFL6
http://www.amazon.co.jp/exec/obidos/ASIN/B00005FFL6/
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Pops on Broadway (ポップス・オン・ブロードウェイ)
ASIN: B00005FFL7
http://www.amazon.co.jp/exec/obidos/ASIN/B00005FFL7/
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Pops on hollywood (ポップス・オン・ハリウッド)
ASIN: B00005FFL8
http://www.amazon.co.jp/exec/obidos/ASIN/B00005FFL8/
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Swing swing swing (スイング・スイング・スイング)
ASIN: B00005FFLA
http://www.amazon.co.jp/exec/obidos/ASIN/B00005FFLA/
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Digital juke box (デジタル・ジュークボックス)
ASIN: B00005FFLB
http://www.amazon.co.jp/exec/obidos/ASIN/B00005FFLB/
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American the dream goes on (アメリカ、ザ・ドリーム・ゴーズ・オン)
ASIN:
B00005FFLC
http://www.amazon.co.jp/exec/obidos/ASIN/B00005FFLC/
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Meta spectacular (メータ・スペクタキュラー
[LIMITED EDITION]) ASIN:
B00005F6TY----this item is temporarily OUT OF STOCK
http://www.amazon.co.jp/exec/obidos/ASIN/B00005F6TY/
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Good luck in yor search!!!