This is an erotic book in which fans of Shiro Emiya-kun and Muramasa are gathered and interact with each other.
*It contains sexual descriptions of Muramasa x Shirou, Mob x Shirou, Mob x Muramasa, and Shirou x Muramasa.

The "Unofficial Fan Appreciation Festival (Kansha-sai)" is a special event for Shirou Emiya-kun, the main character of Fatestay/Night.
In which Fans, who find meaning in life through Shirou Emiya-kun's existence, are invited to be a part of it-----
It is a meetup between fans and Emiya Shirou-kun, where the fans express their gratitude and appreciation towards Shirou him.
In this volume Senji Muramasa also makes a surprise entry.