“Welcome to Moonbase 13, everyone. We call this place ‘The Garden’.”

The year is 2199.
At long last, the march of science has allowed androids to observe the human soul — the “ghost.”

Gentle-hearted androids have been given a role: to resolve the regrets and lingering attachments of ghosts, and so to save their souls.
Da’at, our protagonist, is an android intelligence still partway through its education. Awakening on Moonbase 13, the Garden, Da’at takes up that very work.

This is a story of the bonds formed between kind-hearted androids and ghosts with troubles of their own — and of the pursuit of a bell, tolling unnoticed, that will bring the world to its end.