How do I get into the locked bath at night?

Skyloft Academy's bath is locked at night as someone (not posting the spoiler here) is in there. I've been able to get in through the chimney to sneak into Zelda's room at night, but I notice I can't use my tools inside the academy.

At any point is it possible to break into the locked bath?

It's not possible, although there are claims you can do it through a glitch in-game.

From Zelda Informer:

Well, this video claims to be a glitch that allows you to enter the bathroom and get closer to the completely-naked Gaepora. From what I can tell it is most likely a hack as we cannot replicate the glitch, and the video shows that the game has already been hacked to remove the shield meter, rupee amount, and to add a superman jump. So, its not necessarily a glitch per se.

With that said, the video below shows Gaepora bathing up close, who happens to have no legs, or other parts for that matter. Understandably, there's no reason to animate below the water seen as we're not supposed to be hacking and glitching our way into the tub with him.