This is a super cute one-shot. I always think it's ambitious to introduce supernatural elements to a one-shot because there's obviously not much room to explain them and expand on them so they often end up being a bit scant or superficial. In Toshokan no Youkan, I actually thought the supernatural elements were used really effectively as a story-telling device. The youkai becomes sort of a manifestation of Hashimoto's feelings when he's too shy to act so it has a purpose, it informs his character and it adds a more original element to what would otherwise be a fairly standard shounen-ai story. The story itselfis cute and wholesome but not very detailed or complex. It does it's job well enough but I feel like there could have been a couple more scenes fleshing out Hashimoto's character a bit more or explaining a little more about his relationship with the demon.

The biggest selling point for this one-shot is the art. It's definitely a love/hate situation because it's very stylised but I happened to love it. It's sketchy in the best possible way because it really does manage to look dynamic. It reminded me a little of the art in Doukyuusei.

Overall, this is very cute. It has a great art style and is something a little bit different with the added element of the youkai. The ending is a little rushed but I'd still recommend checking this out.