Good. Then you are in the right place.
The sushi rolling mat can be very useful, although, with some experience - you can do without it. The rolling mat is used to maintain even pressure from all sides of the sushi roll while rolling it.
Hangiri is a cypress wood barrel/tub used in the sushi rice preparation process. Its main function is to make the rice cool faster due to its unique shape, and moisture obsorption ability.
Nori is a paper like, edible, toasted seaweed used in most kinds of sushi. The nori is actually the part that holds the sushi together.