Mizutamari ni Ukabu Shima - Vol. 2 Ch. 6

[MangaDex]

 

[Rozzak]

Seriously, how this girl getting suspicious over something like that? Children have the memories of goldfish.

 

[justforthelulz]

@Rozzak
True, but Futaba is very likely aware of how close the siblings are, given how infrequently the mother is at home.
It wouldn't be a stretch that something as important as Nagisa's birthday would never be forgotten by real!Minato.

 

[thirite]

@Rozzak I don't think Nagisa is getting suspicious of anything, she's just mad at "Minato". However Futaba seems to be pretty well aware something is up, but she's not sure what.
Edit: Oh, nevermind, I see what you meant. Hah.

 

[caitsith]

Man, you really have to feel bad for Nagisa, losing her brother the day before her birthday.

 

[Knonderd]

Nice to see that the author still active on creating manga. So far the story has been really good and I hope it will stay like this until the end.

 

[Oured]

He'll probably be able to excuse his odd behavior and dodge suspicion by claiming their mother leaving them behind forever at the amusement park "made" him like this.

 

[Nixnaw]

Minato is living life on extreme hard mode, I'm not sure how an elementary preschooler will be able to escape the police and the crime members. Nagisa should find her 'brother' odd sooner or later but its quite a leap of faith to go from that to thinking that her brother's body has been swapped.