I wonder if they need the water in order to be able to move about as they please. It wouldn't be surprising if that's why they tried so hard to stop you as soon as you went for the drain.

[ Haru hums in pensive thought but hops back into the empty (if still gruesome-looking) bath. She pauses, then half-bows politely, despite looking like she walked out of a horror movie. ]

My name is Haru Okumura. It's a pleasure... well, the circumstances aside. I'm glad I could help.