Well, it's not a huge spoiler, since it's just the name of the jutsu (unless you go look up the description, but that's yer own fault for spoiling then). [img]i/expressions/face-icon-small-wink.gif[/img] Anything else about the move's details or background will be giving a lot away, though.

And the jutsu isn't using water. That ball in Jiraiya's hand, that's all chakra. The impression that it's water-based probably comes from Jiraiya making Naruto train by swirling water in water balloons with his chakra.