Shinjuku Chapter 15

I killed like 8 of them before I ran out of patience.
No drops, and the guide doesn't indicate that they drop anything at all, unless my luck is just that bad.
If 8 mobs don't drop a chest, chances are none of the 200 will, and it would be tilting beyond belief if even they drop something, its a brown chest, and brown chests never have anything good.

I do wish you luck in clearing all 200 of them if you do decide to try it though, as even the Hornets NP damage is pretty decent, and its going to take hundred and hundreds of turns to kill every single one.

This begs the question: did folks on the JP server actually kill all the hornets and count them all?

There are indeed 200 hornets, none of which drop anything. The only objective of the fight is to break the boss's first bar. It is not worth spending your time doing anything else in this fight.