Onii-chan Is Done For! - Highschool ONIMAI (Doujinshi) - Ch. 126 - HS - Mommy Genes

[KamiCatThem]

unknown. in canon timeline it hasn't even been a year and their new body hasn't reached the point where they'd start growing, presumably

I think it might be a weird cultural quirk. I've read a couple where the character is genuinely trans, going so far as preparing for bottom surgery, and the younger siblings still use original nii/nee

Hmm? They've celebrated two New Years, so it's been a bit over a year at least

 

[tarrasqueSorcerer]

Hmm? They've celebrated two New Years, so it's been a bit over a year at least

Close to two years at this point.
The manga began in summer. Then he entered school (1st year middle) in autumn and studied the rest of school year until spring. Then entire 2nd school year until next spring. And unknown short time of the 3rd year. So it's late spring or summer again now.