Mentioned Characters: Yukari

"Seeking a miracle, the maiden prays, dreaming of a time still to come. What departs may never find its way back, so she holds it close, never loosening her grasp." People call Yukari Yakumo elusive, as though she were some god or oni slipping in and out of sight. But gods and oni are only people she knows, never her. She's the youkai responsible for humans being spirited away, hiding them from the world. And being a youkai, she stays hidden herself. The true Lost Word is the one word that exists nowhere―never written, never spoken, never even thought of. You are destined to speak it someday, and no one but you can do it.

Boundaries "There's a small shrine in a country to the east..." The youkai suddenly speaks while hugging herself. A shrine sits over the boundary to keep evil, otherworldly beings from breaking out. Long ago, this land must have been a meeting ground for the country's most formidable practitioners―mountain ascetics, Buddhist exorcists, prayer-healers, hidden onymouji, and perhaps even Christian exorcists. They all gathered to put down youkai, demons, vengeful spirits, and other supernatural beings. But when the sealing was finally complete, the youkai and their hunters had both vanished. Now only a single, carefree shrine maiden remains, and her shrine is called Hakurei Shrine.

The Boundary Between Nothing and Something What lies in the space between "nothing" and "something"? Why do some things exist while others don't? Why, for instance, does this world exist? Modern science is merely a religion like any other. Cyclic cosmology claims the universe endlessly expands and contracts, reborn each time. Which is really just reincarnation dressed up in different words. Then there is black hole cosmology, which says our universe sits inside a black hole, and that another universe sits inside every black hole within ours. Which is really just the interconnected relationship of yin and yang, worded differently. Finally there's block universe theory, which says every possible state of the cosmos exists all at once, with past, present, and future being mere concepts rather than realities. This is the exact same idea as Universal Reincarnation. Even the idea you just had and believe is your own was likely conceived by someone else long ago. Remember that well, and remember it always. Don't let your brilliant ideas go to your head, and don't fool yourself into thinking you've created something from nothing.

The Boundary Between Reality and Fiction Gensokyo accepts all things, without exception. "Should you ever lose something essential, be it your very existence, the awareness others have of you, or even your life itself, Gensokyo will surely welcome you in. And when that moment comes, you may be asked a question. What kind of being were you? What did you live for? You must not falter when answering. The ultimate goal of all living beings is to make a good life for themselves once they've entered Gensokyo. Hesitate, and you give yourself away. Then Gensokyo will become a place more terrifying than Hell and more dreadful than Makai. A cruel fate indeed."

The Boundary Between You and Me When an idea suddenly comes to you, seemingly out of thin air, have you ever thought that it might be a message from a friend you've never met, reaching out to you from across a great distance? It might be from a foreign land you've never visited, a tropical island you've never set foot on, or another planet entirely. People live there, going about their lives. It is a whole world of its own. You can't intervene in that world, but every so often, a letter arrives, telling you of it. And so you read it, and write back. That reply you write is the thing you've made. Proof that something crossed the boundary and reached the other side. The undeniable evidence that a prayer was heard. The shrine maiden will receive your reply and will surely set to work. "When something that doesn't belong slips in, you have to get rid of it."