CREATE TABLE table_name_43 (opponent VARCHAR(255), record VARCHAR(255), location VARCHAR(255), method VARCHAR(255))
What is Opponent, when Location is "Tokyo , Japan", when Method is "Decision (unanimous)", and when Record is "4-1"?
    
SQL: SELECT opponent FROM table_name_43 WHERE location = "tokyo , japan" AND method = "decision (unanimous)" AND record = "4-1"