Table schema:
CREATE TABLE table_1315616_1 (date VARCHAR, mediator VARCHAR, red_team_host VARCHAR)

Question: On what date was Keiichi Ubukata the mediator and Mitsuko Mori the red team host?
SQL: SELECT date FROM table_1315616_1 WHERE mediator = "Keiichi Ubukata" AND red_team_host = "Mitsuko Mori"