I think I have the gist of this down but I want to make sure I have the nuance right.
宮村：この時間は俺だけのものだーって思うし
I’m interpreting this as Miyamura proclaiming something like "well, this time
(of not wanting to have your appearance “like this” seen by others) is only something I should worry about (and not you) as a way to reply to Hori saying
堀：それは私もおもうよ
Is this on the right track?
Ignore, speech bubble confusion!
are those not the same grammar point? って as a casual topic marker and casual と?
They’re the same entry on bunpro at least. I was sorta under the impression that using って as a casual は was actually just a function of と
Edit: Looking again, I don’t think it makes a ton of difference here, both replacing は and と make about the same sense to me depending on how you read that line break, but i think you’re right, it’s probably more likely と here, she’s either omitting a と言った or some nominalizing thing and 言った feels slightly easier to drop
Regardless, って does things a lot, worth knowing it can do things
Let’s ignore the ーって思うし part for a sec
この時間は俺だけのものだ
This is an AはBだ sentence
A = この時間
B = 俺だけのもの
俺だけのもの → only my thing → only mine
This time is only mine
って思う here is likely closer to “I feel like”, than an actual “I think”
so personally I’d translate this as
“This feels like it’s only for me”
Convo being:
H: “I’d hate if other people would see me being like this”
M: “I’d hate that too”
M: “(Because), it feels like this is only for me/this is only mine”
Also, do check the previous bubble, that’s Miyamura speaking, and it’s いや, not 思う
That, and aside from the fact that she’s straight-up quoting what Miyamura just said, you also can’t stick は straight on the back of a verb. 会ったは is not grammatical. 会ったと is.
I believe we are saying the same thing, I just phrased mine poorly 
You know what, I think I got totally confused by one mere speech bubble 
Hori does indeed go:
それは私も嫌よ
On the previous page, BUT this is actually in a thought bubble and not an out loud direct response to Miyamura saying how he likes that only he really knows about Hori’s other appearance and wants it to stay that way. This is where my confusion stemmed from.
Miyamura going “この時間は俺だけのものだーって思うし” on the next page is then him following himself up saying “well, this time with you in this state is only for me I feel like wink wink” and that’s why Hori afterwards gets all like “Idiot, you’re embarrassing!”
This somehow clicked after reading over it like 30 times and then cross-checking it with the English version to be extra sure, and that’s the nuance portrayed there as well.
No worries, thanks for confirming! I noticed you didn’t update the main thread so just to confirm here - will that mean next week is 40 - 59?
Makes sense! As others have said, it didn’t come up while searching Jisho so I appreciate your explanations 
This is actually really helpful, I haven’t noticed the distinction before. Thanks <3
Well, this week felt quite easy !
Only the last bit is slightly unclear. That and the muscle thing. But let’s just forget about the muscle thing.
Souda : おねぇちゃんの「バカ」はいっかいいうととまらないんだよー
As we all know, Japanese kids don’t speak in kanjis. How could they ? They don’t now them yet, duh.
I think it is:
お姉ちゃんの「バカ」は一回言うと止まらないんだよ
So, “when my sister says “idiot” once, it just won’t stop”
He basically saying to Miya “dude, believe me, you’re done for”.
Miya then goes:
学校での
堀さんがイヤって
訳じゃないけど
そうやって
怒ったり
家では飾り気が
なかったりする
こっちの
堀さんの方が
がわいいよ
It’s not that I dislike the Hori from school but, I just mean that the way you get angry, […] etc…
That Hori is more cute. <3
And finally, that last bit:
他人には見せない時間の共有者になった
Oof. I’m mostly confused about that 他人には at the beginning…
“We became co-owners or moments where we are not seen by other people”.
Or, in a more natural English:
“These moments, unseen by others, became something that we share together”.
I.e. it’s no longer about Souda. they came to enjoy this time they spend together, as their “true selves”.
What’s with that 他人には though ?
You know, I at first I found this manga a bit cheesy and also didn’t like the drawings. But now, I’m hooked. Can’t wait to continue. This is cute.
That whole thing is a subclause
他人には見せない時間
The time (we) dont show others
Fyi, 見せる is to show someone
Btw, the kid is Souta
I want to double-check myself before updating the home thread, but it should be 41-59, I think. Pg. 40 is the blank page just before the “between chapter” bits. There is also a new chapter start page in there, on Pg. 43.
[Details=Pg. 39]
Just to expand a bit on this, in case you are confused about why it is には vs に, adding the は creates a stronger emphasis on the 他人. It would be perfectly grammatical to just use に, but by adding the は, it really emphasizes the idea of 他人 – focusing heavily on the fact that the moments are shared by just them and absolutely nobody else.
[/details]
“We became co-owners of the time we don’t show to the others”
Always knew miyamura had his way with words
With a square box, I think this one is Hori. She’s been our narrator throughout the chapter. 
I think you caught me not actually reading the part, huh
When Miyamura is listing Hori’s traits that he doesn’t want other people to see, "料理してるとことかね”, for example, what is the function of the "とこ” at the end of the verbs? I recognize the とか～とか pattern, but not the extra "とこ” part. Is it short for something? Maybe "ところ”? I feel like I understood the overall sentiment of what was being said, but would appreciate if someone could point me towards a breakdown of this grammar point.
I do believe it’s ところ. Besides the obvious “place” meaning, it can also mean a point in time. Basically meaning “when”. とこ is just the more casual version
I forgot that 所 can be used for time as well- that definitely helps make sense of that page. Thank you so much!
And it is also commonly used to express “things you like about a person”. Eg どんなところが好き？
With regards to your question, @HiroXHiro!
堀さん学校での姿とは違い家ではスツピン主婦業に勤しんでいる。
Unlike Hori’s appearance at school, her home appearance is one of a person without make-up and devoted to housework.
Is スツピン = すっぴん = 素っぴん = face with no make-up?
Yep, pretty much