https://www.dlsite.com/books/work/=/product_id/BJ081911.html
https://book.dmm.co.jp/detail/b165aisat00458/

translation info:
raw: https://e-hentai.org/s/32979f982b/894422-96
group: desudesu https://desudesu.mangadex.com
commissioner: espeon https://gender.tf

read early and support more gb at https://gender.tf !

So its basically a hentai version of the manga I'm worried my Childhood Friend is too Cute!?

Since that's what it looks like. Even the premise about her gender being unstable is the same.

Base +12, asdfghfd +7, venom17 +6, Raj8 +8, Soldier A +6, IngmarS +6

Its actually kind of sweet and I love the fact Mitsuki actually kept that charm for all those years before they started switching genders and that for all their problems he's actually going to stay by her/his side.

Base +6, reroda +14

There is a manga called I'm worried my Childhood is too Cute!? that have the same premise as this one. Basically, this is the hentai version. Also, once Mitsuki reached a certain point Mitsuki either become a boy or a girl permanently. Well, I hope she becomes a girl.

Base +3, Gabygabycandid +6

Typo on page 4
it meal> it means

Base +6, IngmarS +6, venom17 +6, SapphireJack +7, Rod_Perv +6, Penumbral +6

So this is what gender fluidity is....

Base +19, Moroboshi Yuumei +7