It's not unreasonable from just his perspective but any any pov apart from the the FMCs. Romcom protagonists aren't known for their brains anyways and since she refuses to talk what else our guy is supposed to do? It's stupid to think someone would remember you when you only met them ONCE during childhood and that too after she has gotten so much of a makeover since then. Ofc, teenagers acting impulsively and immaturely isn't anything new but it's not like we don't get called out for it. You can't say "Oh, she's a teenager so it's based". When someone is in the wrong you point it out.
Douguchi being so inflammatory is so
weird in this chapter, for a series that's been relatively self-aware and sensitive so far. If you're only looking at the way the manga pages themselves regard Douguchi (and not what she's saying) then she's presented as having a very cool vibe, being wise and clever, cute and friendly, and doing the right thing. She's initially concerned and sincere, gets blushy and earnest, and the only "mean" faces she makes are stylized as silly/cartoonish. And yet the crap that's coming out of her face seems completely detached from reality.
It's such a disconnect that I kind of want to see the raws just to see if there's been some nuance lost:
- On my first pass reading it, I hitched on "can't help but take her side" and thought to myself "I guess they mean 'I will always have my girl's back' or 'I understand her feelings' rather than actually taking sides, because there are no sides going on here. They aren't fighting. The FMC immediately apologized for running off. Fight over, but mutual avoidance ongoing."
- The "things about him that piss [Douguchi] off" I could only reconcile as "well, the fact that he's coded as neuro-atypical means he's more likely to hurt the FMC via awkwardness, but it doesn't seem like she's holding that against him, so I guess she means 'things that are frustrating about him.'" Is she mad that the MC hasn't once tried to approach the FMC at school, or approach her through her friends, or otherwise tried to fix things? It's all I can come up with.
- Does she seriously mean "mad" when she says "no wonder [FMC]'s mad," and not "hurt/upset" instead?
- Why does she pull that face? "Because he didn't infer the whole story just based on her reaction" seems too dumb to be real. Was it "You guys haven't even talked about that?" or "Dude literally everyone else in our grade knows this why don't you?" or something?
If all you read is chapter 5, you get 0% anger or other negative vibes from FMC toward MC personally. She's already scolded herself and the last thing she's texted him is "sorry." When they accidentally come face-to-face, she doesn't glare at him; she bolts like a startled bunny. Between that and her starting to text him back "Hey, do you remember back-" but the deleting it, the mindset I get is literal avoidance:
"I'm afraid that if we talk again and I reveal who I am/was, he'll actually say 'Who?' and that will completely break my heart."
So it's weird to the point of gaslighting that Douguchi makes it sound like this is an argument they're in the middle of. But it's certainly convinced most commenters that the FMC is angry with him for not remembering her. Douguchi is supposed to be very socially capable; she should know better. If there's no TL issue, this chapter's kinda insane.
(And I assume Douguchi would point out to Mizuguchi that she was fucking up unless Mizuguchi prefaced the whole story with "I fucked up so baaad~" which she probably did. But if a gyaru is gonna privately correct her friends and publicly have their backs, I don't hate it.)
Edit to add: Went and looked at the first half, translation seems technically accurate and good (minus pg.4 where "I think I already know the situation, but... it's about Seika?" should definitely be more like "I bet you've already guessed, but... it's about Seika." with Douguchi speaking both lines) But I don't think it captures the tone and nuance for e.g. pg.5/6 where she's being really conciliatory and explaining that her position isn't about who's right, but loyalty and wanting to protect/stand by her friend. And that "things about you that piss me off" is more likely to be "how you're being right now is getting on my nerves" - more about points in how he's handling the situation than core parts of who he is. Also, while the JP doesn't technically specify either, I think it's a mistake given context to choose the present tense on pg.11 when it could also easily mean "well of course she got mad" without the implication that Seika's anger is ongoing.
The vibe I get is "Dude, I know my bestie started it, but for her sake and yours I need you to try and make up with her because I can't convince her to make the first move and ignoring each other is really hurting her. You're killing me, here."
Overall I think there's a just-as-technically-correct TL wherein she comes across WAY MORE LIKABLE. But this shit's hard, so no shade, and I appreciate KDT's hard work. 