Nick: He's had this original clothes this whole time tucked in his room but that's pretty much all he had on him from where he was taken along with his uncle's watch that functions as a token.

Coach: A katana, a shotgun, and the clothes off his back.

Vivi: - A (forged) ticket to a play he wanted to see
- An assortment of cards from the card game Tetra Master
- His robes
- magic armlet
- Oak staff

Everything he wears pretty much has properties that boosts his magic or grant him immunity to certain things, like poison. Those enchantments can easily be removed/watered down by the Capitol too if it comes to that.