My Stepmom's Daughter Is My Ex - Season 1 Episode 3

It's nighttime at the Irido residence. Yume has somehow found herself with Mizuto's boxers in her possession. If Mizuto were to find out, it would almost certainly mean she would have to face the punishment of admitting to being the younger sibling. Hoping to avoid this outcome, Yume waits for Mizuto to fall asleep before heading to the bathroom to return his underwear to the laundry basket. But who does she pass in the hallway, but a bewildered Mizuto, mouth agape, with Yume's very own bra dangling from his grasp.