It’s a snowy day in Namimori, and Tsuna is reluctantly led to school by Reborn along with Lambo and I-Pin, who are in high spirits. To his surprise, his friends are there, willing to help pitch in and take care of the younger children.  But soon Reborn has plotted yet another competition, as the group is split up into two teams and a snowball fight begins. What started as innocent winter fun has turned into a battle for survival!
A mystery.
… ein Rätsel.
Un misterio.
Un misterio.
Um mistério!