first of all, if you are just thinking of getting into this manga, you need to read the prequel Kageki Shoujo! The Curtain Rises before you dive into this. this is a direct continuation of the prequel; the magazine that originally housed kageki shoujo shut down, so it needed to find a new home. that's why the story is broken into 2 parts.
second of all, if you're coming here from the anime (which is very nicely done!), you can start from volume 7. BUT read chapter 2 of volume 1, as anime skipped it completely. it features a character that will have more relevance later on!

kageki shoujo is my most favourite manga ever. it features a group of girls dreaming to become musical actresses of an all-female troupe, in-universe version of takarazuka theater. though our main characters are sarasa and ai, the spotlight shines on each secondary character too, thanks to bonus chapters included nearly in every volume. we get to see side stories where other girls are main characters, giving depth to every single relevant person in the story. you can feel the love mangaka has for everyone she's created.

sarasa is a happy-go-lucky otaku girl, whose character you will definitely enjoy if you are big on anime and manga. she makes so many references to other works of various genres and demographics! but she has her favourite: lady oscar of the rose of versailles. now, rov isn't a mandatory reading to enjoy kageki shoujo (though why wouldn't you want to check out rov?!), but i find it touching that a current-running shoujo manga keeps making references to an iconic shoujo from the 70s. hopefully, you can appreciate this sentiment all the same too.

ai (unfortunate name to type in english in the current artificial intelligence environment) is a representative of another part of japanese media culture. that is, she is a former idol. i love idol industry and stories about it, but they often miss the mark of what it's like to be a woman in such a strict environment. facing sexualisation, misogyny, constant obsesson over looks... well, worry not, kageki shoujo isn't your typical story that chooses to shy away from heavy topics. it faces them head on, and ai's entire character is a representation of that. reading comments to anime, i got annoyed that she was categorised as nothing but a man-hating [insert misogynistic word here], but i ask everyone to engage with the story and her character, understand her trauma and her motivations. she is a very layered, complicated character, that will be a joy to everyone who loves engaging in women's stories.

if you're not familiar with takarazuka revue, no worries, i wasn't too when i started reading the manga. but all you need to know is that since all roles, no matter the gender of the character, are played by women there, one of the main attractions of the musicals is bisexual fascination. for that reason, kageki shoujo is one of the only shoujo titles i can personally think of that lets girls be gender nonconforming, and praises it instead of trying to fix it. she's a girl who looks like a boy? awesome. all girls in the story will be all over her.

definitely read this if you like all-girls casts (yes, the manga has some yuri in it too), stories focused on acting, social commentary or literally just for any other reason. just please read this. it's the best thing in the whole world.