It wasn't that he was surprised, exactly.
No, in all actuality, it made quite a bit of sense and did not betray his expectations in the slightest. What was truly surprising about the entire thing, if anything, was that he hadn't noticed earlier. Somehow the little detail had managed to slip through his observation!
Yako sleepwalked. And sleep-ate.
Neuro had been more than aware that she sleep-bit. The first night he had stayed in her apartment, she had fallen asleep on top of him, soon beginning to bite at his coat and shoulder. He had retaliated, of course, despite knowing full-well that she hadn't been conscious. The marks that his own teeth had left upon her arm had mostly faded with time, but not enough for her to want to start wearing sleeveless shirts again, he had noticed.
Yet, somehow, despite staying in her apartment a handful of times since then, it had escaped his knowledge that when she wandered into the kitchen in the middle of the night she was actually sleepwalking. And to add to that, she even prepared herself simple foods and consumed them before returning to her room. He had seen the phenomenon at least twice and had assumed that her gluttony simply could not wait until the morning hours. Not to mention that when he had made small comments to her as she went about her business, she had even given responses.
—Well, very neutral responses more akin to grunts, but responses none-the-less. He had written it off as her tiny brain being even agonizingly slower than usual because of the lack of sleep.
But that night, her escapades to search for a snack had awoken him. So far she had only done such a thing while he was still awake, yet it seemed she had began feeding her black hole of a stomach much later than what he had been suspecting to be the norm. Slamming cupboards, clanging dishes, and the tinkling of silverware; it was not long at all before the demon was roused from his slumber. And in one swift movement, he raised himself to his feet, crossing the expanse of her living room's ceiling to enter the kitchen.
“—Once again, top slug, you cannot wait until morning to stuff yourself full of food,” he said, looming down upon her from above. Yet Yako did not have any sort of reaction besides half of a grunt.
The demon's eyes flashed dangerously, displeasure at being ignored oozing forth from him. First waking him up and then ignoring him? Oh, so very bold and something that he surely planned to punish her severely for. Long legs took a step forward, and he turned her head up sharply to face his own. However, what he was met with was not at all what he had been expecting.
Her eyes were glassy, staring past him completely. That was when it had hit him that she had not been conscious at all. That every single time she had gotten up in the middle of the night to eat, she had been asleep. Really, Neuro didn't entirely know whether he wanted to laugh, or shake his head in exasperation.
She really did have an appetite to match his own. So much that it even moved her body like a puppet when she was unconscious. Truly, she had achieved a new level of gluttony.
—But just because she hadn't been aware, however, did not save her from punishment. She had still woken him up and ignored him. He wouldn't leave such transgressions unaddressed. Another sharp turn of her head cracked her neck in an unpleasant way, and suddenly the kitchen was filled with her shocked screams and the clattering of the dishes she dropped as she was pulled back to the waking world.
“Neuro, what the hell?!”
—There she was.