CREATE TABLE table_64456 ("Kanji" CLOB, "Name" CLOB, "Builder" CLOB, "Laid down" CLOB, "Launched" CLOB, "Completed" CLOB)

when was the ship completed when laid down is 21 august 1925?
SELECT "Completed" FROM table_64456 WHERE "Laid down" = '21 august 1925'
SELECT "Completed" FROM "table_64456" WHERE "Laid down" = '21 august 1925'