A lot of fun indeed!

"Alright, let's search this place, top to bottom~!" Setsuna chirped, as they were closed off in a room with some nice decor. It looked like a pretty fancy living room. Not as fancy as Momo's of course, but that was an unfair comparison. "And why don't we make this interesting?" she winked at Izuku.

"Oh?" Izuku asked, Ochaco and Momo also looking at Setsuna with interest.

"How about this?" Setsuna winked. "Every time you contribute to solving one of the puzzles, I'll remove an article of clothing for you. And if you manage to get me naked, I might even give you a special prize~!" she added with another wink.

Izuku went deep red at Setsuna's flirtations. He knew that she was quite flirty, and agreed with Momo that she had wanted to go further, but he hadn't expected her to go this far with the realization that she could take this as far as she liked within any limits Izuku and his harem themselves had. "...what kind of prize?" he inquired after a moment of thought.

She giggled. "I'll tell you... if you earn it~!" she assured him.

He nodded slowly. He decided to play along. "Alright, I'm in!" They fanned out to search the room. He checked under a table, and found some numbers carved into the underside. It looked like an equation. He also saw a sticker of a red frowning face, and a Mars symbol. "Found something!"

Setsuna, instead of coming over completely, detached her head, and floated it under the table next to him. "Nice find~!" she chirped, and her headless body moved to remove her shoes and socks.

They examined the equation and symbols, and Setsuna, with some quick mental calculations, came to a fast conclusion. "The equation, when solved, equals 12," she said.

Izuku, not far behind, came to the same conculsion. "My second opinion agrees," he remarked, impressed with how fast Setsuna solved the equation. "As for the sticker... that looks like the "angry" emoji to me," he added. She nodded her head in the air in agreement.

"And that symbol... I think it's for Mars," she mused.

"Mars is also a symbol for "male," or "man..." Izuku analayzed. It then clicked. "12 Angry Men!"

"What's that?" she asked, her head turning towards him.

"It's an old, classic American film," Izuku nodded. At her quizzical look, he added, "I'm a huge All Might fan, and he has an American theme, so I looked up some American trivia in some free time," he explained. Her head bobbed in the air thoughtfully. "And speaking of films, I think that cupboard over there has some DVDs in it..."

She wasted no time, moving her head back to her body, meeting it at the cupboard as Izuku got out from under the table. Ochaco joined her, and they quickly ransacked the thing. "Found it~!" Ochaco grinned, pulling out the DVD case, and opening it up. Instead of an old fashioned disc, there was a folded note inside.

"Nice one!" Setsuna nodded to Izuku, and proceeded to reach for the hem of her tank top, and slowly slid it up and off. Beneath it, she was wearing a frilly, skimpy red bra. "Three more articles of clothing to go~!" she chirped at Izuku as she dropped her shirt.