After you check out the shops, go to the Lakitu Info Center. Toadette meets the bros here. She'll be working on the next papercraft here while the bros rescue more Paper Toads. The first mission is Paper Toad Tailgate. A Sandmaargh will follow the bros. Jump after the icon blinks three times. Deliver the Paper Toads to the Lakitu. Just touch them to get them to join the group. Return to Lakitu when you have all 10. Paper Toad Flurry involves catching the Paper Toads before they hit the ground. Blue Toads fall faster than ones. Touch them to catch them. Jumping makes it easier. There are 40 Paper Toads, so stay alert. Paper Toad Peel-Off involves Drill Dashing into Paper Toads stuck to the wall. One is hiding behind a stone brick block to the far right. This must be some papercraft if Toadette needs this many Paper Toads. When all of the Paper Toads are saved, a delivery from Peach's Castle arrives. It's a new Trio Attack, Trio Whirligig. Toadette says she'll start working on the papercraft while the bros save the princesses and deal with the Bowser Jrs. A Lakitu goes on a delivery, so he stops blocking the other exit. A Paper Toad in the village wonders if there are two Luigis, since there are two Marios. We still haven't heard about Paper Luigi. Go through the east exit in the Lakitu Info Center. It will lead to a pipe.
The pipe leads to the part of the mountain with the puzzle. Go east. Cross to the right side of the area, then climb up the dirt wall. Keep climbing and you'll find a Lakitu. He says you can't cross the bridge ahead slowly. You'll need to jump at the end. Go east. There are some bean spots here. At the top of the stairs, someone tells Bowser Jr. to come along. The Kameks are telling the Bowser Jrs. to return to the villa. The Bowser Jrs. don't want to go back as they're playing with their papercraft and the Kameks told them to play here. Paper Kamek says the bros will be here any moment. Paper Bowser Jr. isn't scared of the bros, especially with their papercraft. The bros walk up and the Kameks notice. Paper Bowser Jr. wants to crush the bros with the papercraft, so some Koopas appear. Toadette appears with the newest papercraft: Papercraft Peach. It comes with its own parasol, so it can float gently to the ground. When you dash, the parasol opens up to deflect projectiles. It can fly farther with the parasol when tossed. Press (A) just before landing to deal extra damage.
There are Papercraft Mechakoopas here, as well as Papercraft Spikes. The battleground has spikes and large patches of ice, so be careful. The Papercraft Mechakoopas will just charge at you, but the Papercraft Spikes will toss spike balls at you. Deflect them by dashing. If the spike balls miss, they'll end up on the battlefield. Dash into them to hit other enemies. Clear out the enemies to make Papercraft Bowser Jr. appear. It's larger than Papercraft Peach and quite fast. It can easily cross over the spikes and will attack with red shells. Dash over the spikes to cross them without taking damage. Dash into Papercraft Bowser Jr. when it has its back turned and numbers appear to knock it off its pedestal. After Papercraft Bowser Jr. takes a lot of damage, it will fill in the spike pits with snow. Use spike balls to hit the papercraft more easily. It will start shooting multiple green shells. Do more damage and the Bowser Jrs. will complain their papercraft is getting scratched up. They'll drop bombs. Dash into them to send them back to Papercraft Bowser Jr. Keep attacking and keep healed to win. You may want to clear out the other enemies before dealing with Papercraft Bowser Jr., but it can generate more.
The Bowser Jrs. are upset that their papercraft was destroyed. They blame the Kameks for making it so flimsy. Kamek tried to warn them, but Bowser Jr. finds the advice less than helpful. All four leave for the castle. Walk to the east and you'll find a red disk with Bowser's emblem on it. The bros grab it. Starlow thinks it's familiar, so it might belong to in the Twinsy Tropic Dungeon. Peach screams nearby. Go east. The Bowser Jrs. are leaving and the Kameks are carrying the princesses on their brooms. The bros rush to save them, but Mario and Luigi fall off the cliff. Paper Mario jumps after them and makes a parachute for Mario. Luigi doesn't have anything, until Mario catches up with him. Starlow and Mario are impressed with Paper Mario, while Luigi's face down in the snow. Mario wants to try, but can't. Starlow doesn't know where the princesses are, but Mario thinks the red disk from before might be important. Suggest that they saw it in the Twinsy Tropics, in the dungeon, on a suspicious wall. Starlow thinks it may be the key to getting into Bowser's Castle.