(Restrictions on extradition)
Article 2.
(8) When a criminal prosecution for an offense committed by the fugitive other than the offense for which extradition is requested is pending in a Japanese court, or when the fugitive has been sentenced to punishment by a Japanese court for such an offense and the execution of the sentence of the fugitive has not been completed or the sentence has yet to be non-executable;
Person sought for different crime
EDIT.