question: On what date was Keiichi Ubukata the mediator and Mitsuko Mori the red team host?
answer: SELECT date FROM table_1315616_1 WHERE mediator = "Keiichi Ubukata" AND red_team_host = "Mitsuko Mori"
context: CREATE TABLE table_1315616_1 (date VARCHAR, mediator VARCHAR, red_team_host VARCHAR)