These are fragments of a connection between two people that have been pieced together. Even if the other is beyond reach, even if they feel like nothing more than a reflection in a pail of water, these fragments are proof that the connection exists at some time, in some world. Warm midday sunlight streamed in through Suzunaan's windows. Children could be heard playing in the village as Kosuzu Motoori quietly turned another page. It's not like she doesn't enjoy playing outside, so why was she indoors reading on a beautiful day like this?

Suzunaan is a book rental store in the Human Village that handles books of all sorts of genres. Kosuzu works and lives in the store, and being a total bibliophile, it seems she frequently reads while on duty. What book is she reading today? What's its genre? Is it a new book from the outside world? Perhaps it's Agatha Chris Q's latest release. Or maybe it's a strange tome that wouldn't look out of place in the scarlet mansion's library. Then again, there's always a chance it's...

Kosuzu Motoori's eyes have the unique power to decipher text written in any language. And that's not just limited to human languages. In other words, she can read demon books―books written by youkai in their own language. As a result, she often gets caught up in the trouble these books tend to cause. In fact, there's a chance she's reading one right now...

Some demon books were written by humans before they died. If a book contains enough strong emotions, and if certain conditions are met, there's a chance the book will resurrect its deceased author as a youkai, which is why such books are also referred to as demon books. As it happens, turning into a youkai is a grievous sin for humans in Gensokyo. If you expose yourself to demon books for too long, they may start to have an effect on you. And that's precisely why the ninth Maiden of Miare warned Kosuzu to leave them well alone. In other words, the act of reading demon books is extremely dangerous. However, Kosuzu is known as the Bibliophile with a Deciphering Eye, so even knowing how dangerous it is, she may have continued reading them...

Kosuzu went to turn the page but suddenly stopped as a customer entered the store. Whether they were there to return a book or to borrow one was unclear, but Kosuzu knew it was time to get back to work. She put down her book and greeted them cheerfully. While she may have put the book down, she didn't close it, and it now lay face up upon the desk. Sunlight poured in from outside, illuminating the page she was on. It read... Wait. Do you think this is a human language? Because if not... Who knows, perhaps there's a demon book close to you as you read this. That's right. There could be one very close indeed.