I follow an anime blog called Tenka Seiha. Most of the posts are episode analysis of currently-running shows. I am not watching any of the series that the author is covering this season, but I still enjoy the exasperated takes.  One line caught my attention from a review of episode 7 of High Card (note: all I know about High Card is that someone’s arm turns into marbles in the first episode):

The real focus of this episode was on the immortal guy though, that he has a sister dying of Sick Anime Girl Disease, known to the rest of the world as Ali McGraw disease, where they’re perfectly fine and win the hearts of everybody until spontaneously spitting up blood and collapsing, only becoming prettier as they approach death.

Anime Girl Disease is very serious, but I dare say it is less common than Japanese Visual Novel Girl Disease.  In my (somewhat limited) experience, Visual Novel Girl Disease often persists longer and has a more oppressively tragic than Anime Girl Disease.  There are quite a few cases of the affliction in the al|together visual novels that I am reviewing (see examples one and two, there are at least two more examples that I have reviewed, but I will omit links for anti-spoiler reasons).  A well-known case that transcends media (since it has an anime adaptation) is Clannad, which I referenced once on site.  But do note that al|together approaches Visual Novel Girl Disease from different angles. Firstly, some of the examples do at least attempt to identify a disease.  Mr. Eno Yamamoto Ten swapped the girl for a boy in one case, a bird in another, and made light of the tropes in between.  We also have various versions of the possibly disappearing anime girl (link omitted in my discretion).  Note:  I have not reviewed Narcissu yet.