Who is the director of the game with HIroshi Sato as the producer on the GBA platform?
CREATE TABLE "group_no_4" (
  "title" text,
  "year" real,
  "platform_s" text,
  "director" text,
  "producer" text
);
SELECT "director" FROM "group_no_4" WHERE "producer"='hiroshi sato' AND "platform_s"='gba';