What's up with this old school drama? First Onii-sama E, now this gahd everyone be dying
Yuri manga from 70s and 80s usually have a bad ending, with death or separation. We had to wait 90s, especially Sailor Moon (1992) to have a positive depiction of Yuri.
I don't know but I pretty sure this was the very first yuri manga
the mangaka's first? and if that is true, no matter how sad this story was, it's still a really nice piece of work.
Shiroi is usually considered as the "first yuri", as it was written in 1971. But technically it's Shīkuretto rabu, dated from 1970. A perfect love-triangle between two girls and one boy. As Shiroi it's a bad ending as the three ends up alone after some suicide attempt and on.
But Shīkuretto rabu was forgotten by history and everyone remember Shiroi as the "first yuri". I even didn't find any scan of Shīkuretto.
If someone finds it, I'm very interested by it BTW!
See here for more information about the first yuri (and yuri in general).