"Mahiru, give me your hand."
It was a day during the second half of summer vacation, and Amane was sitting next to Mahiru as per usual. As he gave her such a request out of the blue, Mahiru slowly blinked in a strange manner.
"What's this all of a sudden? Well, I'm not sure I follow, but here you go."
"There we go."
".. What are you doing?"
"Huh? Fingerprint authentication on my phone."
Feeling rather puzzled, Mahiru directed him a suspicious look as Amane registered her thumb for his smartphone's fingerprint authentication.
"Why's that?"
"Well, you ask why, but I just think it'd be more convenient if we did this. It'd be bad if I couldn't unlock it in a situation where I have to use my phone no matter what."
Amane received an incoming call the other day while his hands were tied with other matters. If it were an emergency and Amane was unable to respond, it would be bad if there was no way to give a clear response.
He thought it would be preferable to have her ready to unlock it with a touch in case something happened, but for an unknown reason, Mahiru's gaze was beginning to show a hint of disbelief.
"I understand what you're trying to say, but are you okay with this, privacy-wise?"
"I don't really have anything to worry about being seen. Well, it's kind of embarrassing to have you see my conversations with others, but it's not like I'm guilty of anything. I can say for sure that there's nothing you would suspect me of, Mahiru."
There was the occasional conversation he had with Itsuki or Yuuta that included some dirty jokes that may be awkward for Mahiru to read, but there wasn't anything that would make her anxious or worried, and since he had limited contacts in general, he didn't have to worry about anything to begin with.
"...I'm not intending to pock into your private life, but are you really sure?"
"I don't really mind at all."
"Not only is it open, it's so clean that I'm bewildered."
"That's the thing. It's not like I'm doing much in particular, anyway. At best, I use my phone for contacting and socializing a little with others or searching for stuff on the internet. I barely take any pictures, either. I'm not bothered even if you take a look at the data in storage, Mahiru."
There wasn't anything in particular there that he had trouble showing her. He only had some contacts of friends, some games, and a photo album with some pictures of him and Itsuki and some of Mahiru's adorable appearance.
As far as Amane was concerned, this was pretty much what high school students were like, but Mahiru seemed to think otherwise, her eyes narrowing slightly.
"It's you, Amane-Kun, so I don't doubt you at all, but in a way, it's amazing that you're erasing any room for doubt on your own."
"That's not the reason I had in mind when I registered your fingerprint, but I guess, as long as you don't suspect me of anything in the end, that's fine as well."
".. Would you like to register yours on my phone as well?"
"There's nothing you're worried about me seeing, Mahiru?"
"Nothing of the sort."
"I wouldn't be surprised if there's a picture of me in there that I don't know about."
Mahiru didn't seem particularly troubled by it, but in a sense, Amane felt like there was bound to be something of the sort buried somewhere, so he stared into her eyes, and soon enough, her eyes began to dart around in an easy-to-understand manner.
"I-I don't have anything to worry about you seeing."
"That's the kind of thing that troubles me. I guess it can't be helped."
"Hyah, b-buuut..."
'Just as I thought, she had some stashed away," Amane thought as he pinched at her checks and played with them as punishment, and before long, he heard some high-pitched words that seemed like excuses.
"If you keep doing that, I'll get pictures of Mahiru from Chitose too."
"...I'll have to get a cute picture taken of me; it seems."
"In that case, how about I take them? How about this face, for starters?"
"Th-That's no good!"
Amane laughed as he continued to rub her cheeks softly, and a wholly flustered Mahiru stepped back before covering both her checks with her palms, as if acting with caution.
When he let out a small laugh at her cute gesture, Mahiru protested by slapping at his thigh, her face revealing her dissatisfaction.