CREATE TABLE table_name_38 (event VARCHAR2, location VARCHAR2, opponent VARCHAR2)

Which event was in Tokyo, Japan and had an opponent of rumina sato?
SELECT event FROM table_name_38 WHERE location = "tokyo, japan" AND opponent = "rumina sato"
SELECT "event" FROM "table_name_38" WHERE "location" = "tokyo, japan" AND "opponent" = "rumina sato"