Boomerang

The Boomerang is an equippable weapon which only appears in, being one of two weapons that every party member can use. It can be bought from the department stores of Merrysville and Reindeer for $1100 each. When equipped, it increases the carrier's offense stat by 32. One Boomerang can be achieved for free in Queen Mary's Castle, by opening the present located in the upper left corner in the room which contains six presents. Only one of the six presents can be opened, thus leading to the Boomerang becoming unobtainable if the player opens one of the other five.

In-game description
"Be careful, this isn't a toy. Anyone can USE it  as a weapon."