Mangadex lists this as "Chapter 6.5" because of the order of release, but it's
not set between chapters 6 & 7, hence it's an unnumbered "bonus chapter" on
Ciao+. I figure it could be any time between when Uesugi found out they can't make a second wish (end of chapter 2) and the mall visit the next Saturday (chapter 4). If you want to be real mean, image this happening right after the former, when Uesugi was still expecting to keep attending school as a boy.
The author
retweeted a piece of fanart based on this chapter. I think she's saying the poster is her husband.
Though it does suck not to be able to cut it, short hair is cute.
Short hair
is cute, but the bigger problem is how this kneecaps Uesugi's ability to pass as a boy. Funny that the hair change is a way for the reader to differentiate Keisuke and Kei-chan, regardless of clothing, but quite detrimental for the character. Especially when being really androgynous indirectly lead to Uesugi becoming a girl!
Maybe if Keisuke's perception of what a "girl" is changes it might be possible.
I think not all girls like long hair
I don't see this as Uesugi being
Hank Hill so close-minded as to think girls having short hair is wrong. For one thing, Keisuke's "boy" hairstyle is barely shorter than his
mom's hair. I think this
specific hairdo was undone because it is (by intent) masculine
to Uesugi. In fact, the hair didn't grow back as Eito was cutting, only when Uesugi saw it made them "look like a boy."
Funny idea how I think this could work: Imagine Keisuke's big sister got a haircut like her sibling used to have. Keisuke still doesn't understand what Tobi said, but guesses she can do something Eito couldn't. After nee-chan cuts it (for some exhorbitant price/favor), the hair stays but only because Keisuke was still wearing a girl's school uniform. As soon as Keisuke changes into boy clothes, the hair changes back again.
Of course, since this a "bonus" chapter, I don't expect the hair thing to come up again.