Find some Takarazuka elements in shoujo manga or anime series-- OTHER than the following: Utena, Princess Knight, Rose of Versailles. Note that the mention or appearance of Takarazuka (such as in Ouran High School Host Club) isn't the same as the series actually containing “elements of” Takarazuka!
Ok, so Sakura Wars isn’t “shoujo” but I think it makes a much more interesting question–how does elements of Takarazuka work in a shounen/seinen title like Sakutai?
All I could think about in terms of shoujo titles along that line (at first) would be stuff like Marimite, where a big key here is that the girls take on roles that a guy would–well, more like within a certain liberated confine (a walled garden if oxymorons are not your thing) in which the gender roles are reinvented in an unisex fashion to cater to certain mainstream fantasies about womanhood. (Or manhood.) We could find these “elements” in even perhaps shows like Natsume Yuujincho, which a real-life adaptation would fit its untamed, undead, and ungendered host of ghosts. It doesn’t matter if you carry one or two X genes in your chromosomes, as long as you can scream with your emotions in style it’ll sell. Actually Natsume would be a good example, and I always want to write about how Natsume the boy is such a patsy compared to his yankee [the Japanese slang] grandmother, and what does that signify. Maybe some other time.
To me, it’s clear that there is no one answer, or one mechanism or element that makes Takarazuka Revue attractive to its predominately-female audience. And short of mentioning that not all yuri fangirls think alike, it’s just common wisdom to pepper your work with all the elements you love, of that genre. Because maybe more people would love your work if there are more elements of things people in general like to see?
Which is why the whole idea about pinning Takarazuka Revue’s charm points from shoujo manga a bit like shooting fish in a barrel. (Admittedly it’s a barrel I do not read, and do not want in general, so this is real “homework” to a degree.) It’s just much more exciting to see it play out in seinen/shounen works like Sakura Wars, or Hitohira (does this really count?), or a very deep read of the Sola anime. Because you don’t expect to see it there, yet there it is.
(For Sola, I look at it from a context that there is a whole slew of late-night breed of anime that resemble stage plays from a script compositional standpoint. I am not sure if many of them have “Takarazuka elements” or whatever but those showgirls are relatively well known in Japan. They leave a mark in the mind of some, and it’s not just some superficial reference usually. Maybe sometimes it’s an subconscious imprint which affects people or the arts as practiced locally. At any rate it’s a long shot.)
But perhaps all of that is just a coincidence. To be honest, a major theme in Ouran High Host Club is Haruhi’s personal development through interpersonal relationships, and how that is a way of feminine empowerment in Haruhi’s own context. A big part of Haruhi’s story is invariably entwined with the identity of a woman lawyer, an identity taken by her mother. Suddenly Phoenix Wright seems a natural title for the Revue to do, and it is well.