The Lady of the Endless Castle

Japan, the end of the 16th century. Akechi Mitsuhide's vassal rebelled against his lord Oda Nobunaga, who began the unification of the fragmented Japan.
After killing him, Mitsuhide seizes power, but Nobunaga's other loyal vassal, Toyotomi Hideyoshi, appears to avenge his master.
So says history. But what if she is not the only possible course of events? And what can its ramification lead to?
"Lady of the Infinite Castle" includes everything that makes Kago's work unique. This is a story in its own genre that goes beyond science fiction, beyond violence and beyond imagination. For your first acquaintance with his work, this is the best choice. — Tito W. James

It's a story about a world breaking up into billions of infinite worlds, similar to the classic sci-fi trope of "parallel worlds."
While stories like this have existed in many mediums (novels, movies, comics, etc.) before, I think this one, Lady of the Infinity Castle, represents a new way of showing parallel worlds that I've never seen before.