I get that this is translated literally, and I know that some people prefer that. I don't, and I wish it sounded more like how people speak.
There's a lot of ways to adapt english speech to writing. From understated dialogue like Mamet to epic dialogue like Tolkein, but none sounds like this. Rather than belabor the point, I'll just give a small sample of what I mean. Take page 4. Here's the original:
Child: Uncle, are you some great person?
Mother: Hey, stop it.
Mother: I'm sorry, it's a different look to the people around here...
Hermann: No, I'm an ordinary uncle.
So, here's my thoughts. For context, I don't speak japanese and I've never been involved in translation work.
The child's line: This is likely "Oji-san," which in japanese can literally mean "Uncle." But Uncle in english simply isn't used that way. Oji-san is used generically to mean "older man." He also asks if Hermann is "Some great person," which I said out loud a few times to test and doesn't really work for me as dialogue, especially child dialogue. Given the speaker, I'd try this line as:
Child: Mister, are you a bigshot?
I'm not in love with "Bigshot." "Are you important" would be more faithful but is phrased awkwardly, especially for (again) a child's mouth. Regardless, I dislike the use of "Uncle" here.
The mother's lines: I don't love "hey;" taking such a casual tone when disciplining her child contrasts with her formal tone when speaking to Hermann. That's a preference thing, and I get that. Since she's trying to be proper in public, I'd try to adapt her chiding to her child to reflect somebody gentle yet firm. "Hey, stop it" seems like something you yell at a malicious act to me, not an ignorant one.
Her second line is more egregious. "It's a different look to the people around here" isn't how people speak to the point where it's not grammatically correct. "To" is the wrong preposition here. I can figure out what's meant, but it's not how anybody would say it. With those said, here's what I'd try:
Mother: Ssh, don't be rude.
You could take a lot of approaches with this line. This is more or less accurate to the original meaning (assuming that the original line translates to "Hey, stop it") and still sounds like something a gentle mother would say to her child in front of somebody important.
Mother: I'm sorry, you just stand out around here.
Again, many approaches. For a higher degree of interpretation: "I'm sorry. He hasn't met many people with black hair."
Hermann's line: As a callback to the child's line, writing this might depend on what you decided to do up there. But just to massage it into a more natural vernacular, here's two approaches, one more interpretive:
Hermann: No, I'm nobody important.
Hermann: No bigshot, just a man headed to work.
Once again, I'm not a translator and I'm getting this stuff for free. I enjoy it! I'm happy that it's being made. I just wish it sounded more like how people speak.