Special Dagger

Exploration Stage: Room of Fate
From: Huntress
Description: I ran into that unidentified monster again the other day. He attacked me right away. I always carry a koryu sword with me, so I threw it at him. The monster disappeared without a trace, but so did the koryu sword. I tried looking for it, but I couldn't find it. Can you help me find it?
Completed: Look! The tip of the little dragon sword is melted as well as the sword fan! This is no coincidence. This is definitely the work of some dark magic. I have to talk to Isabelle.