Quite a lot.

"Well, first, the girls were dumbfounded about the cars they saw, mistaking them for mini Destroyers," Ria remarked.

"Destroyer? What's that?" Kazuma asked.

"Eh, just a big lumbering machine in this world, you might actually see it at some point," Ria shrugged.

"... hopefully waaaaaaay into the future," Kazuma groaned.

"Anyway, then we went to an arcade, where Darkness, Cremea, and Aqua almost busted up some machines after coming close but ultimately failing to win the games..."

"Not surprising," Kazuma sweat dropped.

"Then Megumin and Xylixia got mistaken for cosplayers," Ria ticked off her fingers. "They had several pictures of them taken..."

"Of course..."

"Then you guys went your separate ways as the sun went down, Cremea and Fio got waylaid by some bikers... Poor bastards never stood a chance, and Fio took their wallets, and found an exotic shop. She ended up buying a bunch of exotic Middle Eastern Harem outfits in various sizes and colors, that's what's in the briefcase," Ria giggled. "Those bikers should know better than to carry around that much cash... Though she was rather worried that those wouldn't come along with her when she returned to this world..."

"Nice..." Kazuma grinned, already looking forward to Fio giving THOSE out... "What else? Did I get my... Business taken care of?" he asked with a blush.

"Kazuma, I'm a Sex Goddess," Ria deadpanned. "You can straight up tell me what was on your computer. And yes, you did go to your house and delete your browser history successfully."

"Oh thank heaven," Kazuma sighed.

"You also left your parents a rather scathing letter about laughing at your death, thinking it was both cathartic and hilarious to prank them with a dead person communicating with them. You mentioned Fio was rubbing off on you," Ria sniggered.

"Well yeah, but hey, not like that's gonna come back to bite me in this world..." Kazuma replied.

"It's a bit uncalled for though..." Ria sniggered.

"...what do you mean?" Kazuma asked.

"They didn't actually laugh at your death like Aqua said. The closest they came to it was admitting it would be funny if you weren't dead, but they did in fact mourn you from the get go. Aqua was just piling on with the "kick you while you were down" thing by saying they laughed before the grief kicked in," Ria replied casually.

"...that bitch... Now I feel bad about whatever I said to my parents in that letter! I'm gonna kill her!" Kazuma growled, shooting out of bed and dashing out his door.

"...should I tell him I did him a favor and snagged the letter so he wouldn't regret that?" Ria mused, holding up said piece of paper. She then heard yelps, banging, and pleas for mercy from Aqua's room, before smirking. "Eh... It can wait until tomorrow..."

(I have no idea if what I had Ria say was actually true, but hey, it does seem like something Aqua at the beginning would do, and even if it does at any point get confirmed that Kazuma's parents DID laugh at his death... Well, first of all, they're assholes... Which would explain a lot about Kazuma actually... and secondly, it's totally in character for Ria to set Kazuma on Aqua for the lolz. And also a bit of her softer side in making Kazuma feel a bit better about the circumstances of his death. Up to interpretation if there's no confirmation either way, so hey, what the hell XD?)