Jean
"So... That large creature went in there..."

Suke would say as she and Rosemary approached the rabbit hole, looking like it would be a hassle to try and squeeze through it. She tilted her head at hearing the odd sound come from Rosemary heading inside and went to do so herself. She stopped for a moment to look at the other girls, specifically Raxia. 

"Normal? If anything you three are abnormal... I cannot sense a heart amongst the three of you."

As bad as that sounded, Suke spoke it in a flat tone more of a matter of fact than an insult.
Alyssa
After everyone had entered the hole, the dirt and roots would eventually give way to bricks and then to smooth walls with repeating patterns. Furniture, from arm chairs to bookshelves to mirrors, would float upwards as they all slowly drifted downwards. At some point, the group would hear the gasp of a young girl. She would drift down and eventually meet pace with everyone else's falling.
Paul
"My goodness how curious! I had seen that rabbit with the tailcoat and watch, but did not even imagine that others would follow him into the tree as well!"

Her dress would poof out like a parachute, almost making her fall slower.

"Did the rabbit invite you to his party? He seemed like he was rather late to something or other."
Robert
*As the other girls began to drift downwards, Rosemary instead simply began to fly, fluttering her wings to keep her afloat. For a brief moment, she forgot the others probably don't have any means to circumvent their descent, so she dove to catch up, but as she did, found herself speeding by them as their drop slowed to a crawl. She remained in place, watching in confusion as they floated downwards*

"Huh? Oh, hello. Uh, I just found this hole thing and followed a rabbit, my curiosity got the better of me."

*She smiled and rubbed the back of her head awkwardly as she spoke to Alice. Unbeknownst to Rosemary, Alice too would only hear a bell in place of her voice. Alice's presence was odd, as she didn't see her go down the hole. Maybe she just got a head start?*
Donald
"Party...? The heck is a party..." Raxia crossed her arms as she was confused before turning to Suke. "Oh yeah... About that... I don't have a heart becuase im whats left from my whole self... A Nobody to be exact, which is the husk of the dead body of a whole person..." Raxia explain, as she didn't realize this was a Heartless at all. "Hope that brief explaination gets stuck to her head..." She sighed.
Jared
"Oooooh!! I think a Party is like people gather for a bunch of food and share conversations!!" Saxtano blurts out, before summoning a singular Lindworm Lance and aimed it at the hole they entered from. "This must be good info!!" She said with a cheerful smile.
Virginia
"If we fight Heartless in this place during whatever the heck a Party is all about... I ain't going to let a single one get away... Cmon girls, we got some exploring to do..." Gioxada said before putting her wooden Scythe on her shoulder, with Raxia and her wooden Claymore following behind her and Saxtano with 5 more Lindworm Lances summoned behind her back followed Raxia.
Jean
Suke let herself fall, not really caring about falling damage for the time being: more interested in where it led. Once she saw the bottom for herself, she used a small Aero spell to break her fall and land right on her feet and looked around. Her attention then went to Alice, since she seemed to be a denizen of this place. 

"We followed the rabbit here. It was... Odd seeing one that big run about..."

As she said that, Suke would glance back at Raxia and the others... Not expecting that kind of answer: but it made sense in some way. 

"Is that so? I had no idea such an existance is possible."