After eating his dinner and washing the dishes, Amane returned to the living room to find Mahiru sitting on the sofa, completely absorbed in some kind of small notebook that she seemed to be reading.
Amane figured that it'd be rude of him to sneak a glance at its contents, so he tried not to look at what was written, though he tilted his head at Mahiru's enthusiasm towards the notebook. He sat down next to her, asking, "Uh, Mahiru- san? What might you be reading?" But in response, Mahiru shuddered intensely and looked up at him in a panic.
"Eh? A-Amane-kun?!"
"Ah, well… You looked really eager when reading that thing, so I couldn't help but interrupt. Should I not have disturbed you?"
"N-No, that's not the case, okay? I-I was just surprised that you started talking to me all of a sudden, erm… that's all."
After a few moments of silence, Amane asked, "...Why're you acting evasive? Are you reading something indecent by chance?"
Amane joked with her knowing that it couldn't possibly be the case, but Mahiru pursed her lips and clammed up. This made him panic instead.
"...Were you actually reading that kind of stuff?"
"I-It wasn't anything indecent! I-It's not like that…"
"If you don't want to share that notebook, Mahiru, then I won't pursue it any further, okay? Doesn't seem like I should ask about it, so I'll just excuse myself now…"
"Th-That's not it! I don't mind showing it to you, Amane-kun. But… erm, y-you won't get angry or upset, will you?"
"I don't think you could do anything that'd make me angry, Mahiru." "Well, erm…" Mahiru paused for a moment before continuing, "Th-Then, here you go."
Mahiru resigned herself to her fate and closed the notebook. She handed it over to Amane, but he lost all strength the moment he laid eyes on its cover. Written across it in large, bubbly, and colorful letters was: Ayaka's Special Guide to Ideal Muscles.
Amane hadn't actually thought it was anything truly obscene, but that it was simply something she'd rather not show to a man, but not a single person would have imagined that such a monstrosity would come into existence, much less for it to be in Mahiru's possession.
With a swift flip through the notebook, Amane was greeted with elaborate descriptions and drawings of different muscle training methods, the most efficient order to do them in, the ideal nutritional balance, the most effective post-training muscle massages, and various other notes jotted around the edges that one would usually expect to find in specialized muscle training books. It was such an intricate collection of notes that Amane's strength was being drained instead.
"...I'll have a word with Kido later. Mahiru, did you perhaps acquire a new fetish…?"
"Th-That's not true! W-Well, putting that aside… You're, erm, always working your hardest, Amane-kun… and I want to help you out, too. I was thinking that it would be better if I was more mindful of the best food I could make to support you."
It seemed that Mahiru only wished to help him and had consulted Ayaka for advice. It was true that Amane tended to train tirelessly, but he couldn't help but feel that her own preferences had some influence over her decision.
"So that's how it was. You've been thinking about a lot of things for my sake, and thanks for that. You're always a big help with the meals you make."
"...Uuu. E-Erm, there's a hint of my selfishness in there, too…"
"Yeah, I know. But since that selfish side of you helps me to improve, I don't think it's a big deal. You can't do everything without a little bit of selfishness here and there, after all. And besides, you basically never tell me how you'd like me to look, Mahiru, so I'm kinda curious what your ideal type is. Is macho what you'd like?"
Amane would've seriously considered changing his training routine to get that kind of body shape if Mahiru preferred a bodybuilder-like figure, but that didn't seem to be the case, for she shook her head side-to-side.
"Y-Your current physique is more than enough, Amane-kun. I think that a slender and toned body is wonderful… B-But I feel like I won't be able to look you in the eye if you train even harder, so this is sufficient."
"Alrighty, then. Time to step up my game." "How did you come to that conclusion!?"
Mahiru's tastes, which she had tried so hard to keep hidden until now, had been revealed. Since Amane was going to be training anyway, he wanted to try to build himself in line with her preferences, which is why he had spoken up, but Mahiru simply shook her head once more, her face beet red.
That aside, it seemed to be where Mahiru's tastes lied, so Amane looked through Ayaka's handy little notebook, vowing to work even harder so that he could impress his girlfriend.