As for typo's...it's okay to point them out.
It had been a little over a week since Akira and I arrived at our parents’ mansion(comma) and although the official reason for coming over was seeing
mother and father appear to be early risers,(semicolon, not comma) I wonder what side of the family I take after
How can you think of drinking alcohol before we('ve) even had lunch? (Present tense)
I’ve never really felt comfortable when she vented about our parents, but (I've) never denied her a chance to do so, even though my own feelings are more nuanced.
We get up, take another sip, (change of subject from "we" to "Emi" should break the list here)Emi lets out a cute little belch that most people would only associate with infants(comma) and we start walking towards the staff building. (This whole sentence should be rephrased; it should possibly be two sentences or at least use a semicolon)
I don’t recall getting particularly bad marks lately(comma) and even if that were the case, a teacher would be more likely to approach Mutou or Shizune in order to get in touch with me.
the room I step into would neither fit into a medical staff building nor a school. (This one just sounds awkward.)
Finishing emptying Lilly’s suitcase, I stand up and get ready to return to my own dorm room. (So does this. Perhaps, "I finish emptying Lilly's suitcase, stand up and get ready...")
Having no other people nearby in a one-mile radius has allowed Hanako to relax to the point where she’s been wearing her hairclip almost constantly(comma) and although she’s still not as chatty as Emi or Misha usually is, she’s calm enough to hold conversations with us without her usual stammering.
Naw, she’s just trying to give us some space. Wouldn’t you do the same for her if it were her and me who just got together? (Me or I? I'm not sure)
I was, of course, a gentleman(comma) so Hanako was given the double bed while I spent the first night in the smaller one.
Hanako merely initiated that because she thought it was the only way to prevent me from drifting away from her(comma) and she was so uncomfortable during the whole experience that it was clear to me in hindsight that she certainly wasn’t ready for the act itself.
It really surprised me when I discovered this about myself. (Awkward; swap "this" with "that", and maybe drop "about myself")
Tomorrow morning would(will) probably be very awkward. But I promise myself to wake him up with a smile tomorrow
The reason for the tension I feel is the fact I just completed my first group assignment in class. (the occasional assignments Hisao and I do together notwithstanding) Or rather, my first group assignment that didn’t end in disaster, like some time ago in science class, when I was struck with a panic attack. (Move the period after the parenthetical)
For a moment we just look each other in the eyes. A mutual look of uncertainty, then of mutual reassurance. (Redundant mutual, should be rephrased. "A look of mutual uncertainty, then of mutual reassurance" or "A mutual look of uncertainty, then of reassurance")
I’ve been using them for the biggest part of my life. (Awkward, use "a large," "the larger," "a big," etc. Also consider using "portion" in combination with some of those)
Hanako’s actually quite the snuggle bunny in private…(space)a
I hang my head in shame, but (pronoun/noun) doesn’t seem bothered by it.
She gives a gentle nod, her smile never leaving her face, and (she) replies with a voice that’s tranquil and peaceful. (You can avoid the "she" by rephrasing: "She gives a gentle nod and replies with a voice that's tranquil and peaceful, her smile never leaving her face.")
__________________________
__________________________
I've
bolded the more egregious ones. The fact that this was all I found in one read-through should be heartening