Both dive bombing, torpedo bombing and bombing by aircraft in level flight, horizontal bombing, were carried out by the Japanese at Pearl Harbor. Horizontal bombing was notoriously inaccurate but was vital should the torpedo bombers, obliged to approach at near-stalling speed, fail. Intensive training increased Japanese accuracy from high altitude (between 10 and 15,000 feet) from 10% to 50%. To penetrate the armored decks of American battleships the Japanese converted heavy, 800kg, 15.7-inch, artillery shells into bombs by fitting fins. The aircraft used were Nakajima B5N2 Kates.
You can find out more about bombing techniques in the following Osprey books: