Nakajima Atsushi found two little girls who couldn't find their parents and brought them back to the orphanage.
Several years later, Shibusawa Tatsuhiko happened to pass by the orphanage.
Nakajima Atsushi pulled a few children over and introduced them: "Dad, this is my fiance, Akutagawa. This is Akutagawa's little sister, Gin-chan, and these are my adopted little sisters, Anya and Gania!"
Shibusawa Tatsuhiko, who didn't recognize any of these children: "???"
Anya had an invisible little sister who couldn't speak. It seemed that only Anya could see her.
With her sister by her side, Anya never felt lonely, even after being moved from one orphanage to another.
Until one day, it seemed like the wind was about to blow her sister away. Anya quickly reached out her little hand and grabbed her.
And suddenly, she was swept away to an unfamiliar place.
"Don't be scared, little sister! Anya will protect you!"
She was a fragment of a world's consciousness, broken and unaware, following a little girl. Just as she was about to disappear, the girl nervously reached out and grabbed her arm.
"Little sister!"
The girl brought her into the human world, where she was born in human form.
Reader's Guide:
1. The Anya sisters are the protagonists, but the story has a high diamond content across three generations.
2. This is primarily a Bungo Stray Dogs story, but the plot and characterizations change drastically. It follows my own alternate timeline.
The reason for Atsushi's personality changes is explained in the eight-year-old bonus chapter of The Day the Weretiger Found a Raunchy Script.
The reason for Akutagawa's characterization changes is explained in the bonus chapter of Are Yokohama's Twin Diamonds in Another World Acting Strange?
For why the other Bungo Stray Dogs background and plot details in Yokohama are different, see the second arc, Computer Spirit, of I Still Haven't Blown My Cover Today.
The reason for the little Black Mud Monster's changes is also explained in Computer Spirit of I Still Haven't Blown My Cover Today, and the first and third arcs of There's No Way I Could Blow My Cover.
3. Of course, you can read this story without reading any of the above. Just treat it as my own setting. I listed them for curious readers and to have an excuse for the OOC characters [attempting to defend myself].
4. Let's all read in a friendly and happy spirit. If you don't like it, we can meet again in another book. Don't fight; good kids don't fight.
Theme: May the world, and you, always be treated with kindness