As if she intentionally wants to make Keishi feel more flustered, Aina crawled towards Keishi's embarrassed face like a cat and looked into his eyes.

"Hero, are you sick?"

"Probably the travel between two worlds made you nauseous?"

Although Keishi feels super awkward, he managed to say:

"Ah, I'm fine, totally fine."

Hearing that, Aina leaned back and sat on the bed, her legs forming V shapes with her feet facing outside.

Keishi sighed with relief and asked:

"Did you say travelling between two worlds?"

"Yes, by agreeing to go through the portal, you, Miyamura the hero-san traversed through world dimensions and reached our country."

"So I really went isekai'ed... This is real... Oh, but maybe it's still a dream... But it feels too real..." Keishi thought. Then he asked something he has been wondering for a while:

"What is the circular shape on the floor over there? Is it a magic circle to summon me to this world?"

Keishi pointed at the mysterious thing that he has noticed for a while.

"Ah... that one, it's a magic circle, yes, but it's for me to travel to another world."

"Oh... you travel to another world on your own! Isn't that awesome? Are you like, really strong?"

"Not really, I only needed to draw it and then imagine the world lines... it drained a lot of my power though."

"Draw? What did you draw it with?"

Keishi was a little curious about the "world lines" that Aina described. He had heard about this "parallel worlds" stuff being portrayed in sci-fi movies but he had never understood it well because Keishi is not good at Physics. But he is more interested in the material used to draw the magic circle.

"..."

It's the first time Aina didn't answer his question, so Keishi just repeated it, thinking that maybe Aina's language is a little different than his.

"Hey, Aina? What did you draw it with?"

"Sali..."

Keishi wasn't able to hear this word clearly because Aina muttered it. So he asked again.

"Sali...?"

"Saliva! My saliva is the secret to draw a magic circle that can open a portal! Why did you have to know that? Mou! Baka!"

Keishi realized he had stepped on a minefield.

"Ah! I didn't know! I'm sorry! I'm really sorry!"

"... I don't mind it because hero-sama was asking me, actually."

"..."