日本と韓国の議論の広場

別物でも同じだ。ソースはウィキらしいから、自分でよく読んでみろ。（猛爆）

http://answers.yahoo.com/question/index?qid=1006050816713
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A study conducted by the Korean Consumer Protection Board (KCPB) at a college campus found an average of 6.1 inches (15.5 cm).[citation needed]
A study conducted by the Journal of Sexology in Japan found an average of 5.1 inches (12.9 cm). (Measured by staff)