"Well, h-heh, I know this isn't really a campout but I think I know an idea for a fun game none of us have tried before. I was spending time with Lemon-tan last week and she told me all about it, something the humans like to do outside when they're in the middle of forests like this one."
"And what might that be?"
"It's a game called Cornhole, but it doesn't actually involve corn. It's about scoring the most points by tossing things into these...boards that have holes in them? Like little bags of rice or something."
"So it's sort of like an old-fashioned game of Horseshoes? Sounds western."
"'Horseshoes'..? Is that some other kind of human game from the Outside World?"
Of course, Renko had never come across real life instances of either in her time but she understood the basics to Horseshoes after incidentally reading about it once and she knew how to play ring-toss games pretty well. The college girl was actually pretty thankful for such a pedestrian game being suggested by the Greater Fairy, it's something she'd actually be able to do without any of the special powers the Fairies must have.
"They must come from the same general area, but I've never played either. Is there much we need for this Cornhole game besides those boards and something to throw?"
"Nope, I think that's all there is to it."

"Never thought I'd have to pull these out, but..." Renko begins rifling deep into her handbag for something she was gifted randomly on campus one day though never had a use for. It's remained in there over the past few years for no greater reason besides Renko not caring to think about it much, but it seems like the time has finally come.
She pulls out a 3-pack of synthetic hacky-sacks still in their wrapping, no bigger than the palm of her hand.
"Would these work?"
"Oh! Those would be perfect!"
"No way...what else do ya got in there Renko?"
"Eh, just the basics."
"Woah, wait wait wait. This is all great and everything Dai-chan, but where would we even find boards with special holes in a place like this?"
"...Oh, you're right. I hadn't actually thought that far ahead..."

"Hold on now you two," Renko says as she stands from the fallen trunk again. "Let's not give up on this too soon." A quick scan of the clearing just beyond where they cleaned up all the bark revealed exactly what the Physicist was looking for. She walks over to two nearby hunks of bark that weren't too warped and seemed just big enough for the kind of boards she figured they'd need. By the time she was back, both Fairies were looking on with awe at the implications before them. If Renko could read their minds right now, the first word she'd hear from them would be 'Genius!'
The college girl grabs her multi-purpose tool and whips out the included blade, ready to get to work.
"Just tell me where to carve the holes and we'll have this done in no time~!"
Daiyousei immediately jumped at the chance to actually try something new and went to brainstorming with Renko on how to place the holes for scoring. 3 felt too typical so 5 ended up cut into the bark while Cirno fooled around with the hacky-sacks. Many times, she'd need to retrieve one kicked too far into the bushes while on one occasion she ended up pelting Renko in the side of the head. "On complete accident", of course. But eventually, they had their boards ready to go.

"Okay, and they need to be slanted. I almost forgot, that way it's harder when you're trying to throw them in." Daiyousei runs off and grabs some more average-sized branches before snapping them in half, the complete setup nearly ready to be tested.
"And what have you all been getting up to in the meantime?"
"Hi Sunny~!" Cirno waves joyfully before the footbag she'd just beaned above her comes sailing down into her own head, the Ice Fairy crying out before she catches it and rubs the spot where it hit her.
Sunny simply laughs as she watches.
"Did Star not want to come or somethin'..?"
"Oh, she's just back at the house making dinner for everyone."
"But we brought every blanket we have~!" The Sun Fairy enthusiastically tosses the entire clump she'd been carrying into the open space next to the Tower. The whole bundle plopped next to Renko as she propped the boards up against the fallen trunk to better jam in the legs.
"I also have some pillows and a few belongings of ours that we thought would be nice to bring. Uh, what /are/ you all doing anyways?" Luna watches in confusion while Renko sharpens one end of each to-be leg.
"This is a game called Cornhole, you toss bags to win. Daiyousei here thought it might be fun to try once you all got back."
"Oh, just like a game at a Festival~! I'd love to try, but we should lay out all the blankets first."
"Star won't be here for another hour or so either, so this should be a nice little time killer."
Once Renko had finished carefully hammering the legs through the bark, everyone agreed to chip in with laying out a different blanket until every single one had been carefully layered together.