Jiraiya is a rather interesting character. From his actions to his slightly obnoxious personality, it sometimes makes me think “How in the world is Jiraiya one of the Legendary Sannin?”. We know that Tsunade contributed with her strength and medical ninjitsu during the war. Orochimaru was naturally a “genius”, so we know that he probably contributed a lot during the war, too. But what did Jiraiya do? We see that he “adopted” the Ame Orphans and trained them in ninjitsu, etc.