Power failure
With a hangover from hell thanks to Tsuande spiking her drinks, Mizu is not happy to be back in school and forced to listen to Pein's LOUD music. She tried threatening him and taking away his radio but he just finds another way to keep the loud music going. So she figured the next best step is turning off the power in the drama room. The only problem is she doesn't know much about powerboxes and the school basement is too dark for her to see clearly which switch belongs to which room. Being a woman of little patience she just starts pushing buttons and flipping switches until she can no longer hear Pein's music. She sighs in relief and heads back up stairs having no idea that she just turned off all the power in the whole school. Even worst she might have broken a few of the buttons in the power box by mistake.
She head back up stairs with a smile on her face "victory is min- oh shit why are all the lights off in the school?" Knowing that she must have done something wrong, Mizu does the mature thing and heads to her classroom to start packing her bag to leave. No way in hell she want to explain this one to Tsuande.