who is the leader of japan?
(JOIN (R government.government_position_held.office_holder) (AND (JOIN government.government_position_held.time_macro 2015^^http://www.w3.org/2001/XMLSchema#date) (AND (JOIN government.government_position_held.basic_title m.02rbq) (JOIN (R government.governmental_jurisdiction.governing_officials) m.03_3d))))