Onigiri is a rice ball, which is sometimes filled with other foods (pickled plum, fish and fish eggs are some of the most common fillings). Eating arancini made me happy because it reminded me of eating my mom's onigiri when I was a kid.
Arancini is prepared by first cooking the rice with whatever flavoring you want to add. So, the rice in the arancino that I ate was first cooked in squid ink! Next, the rice is formed into a ball and covered in bread crumbs. Next, it is fried. Yum!
Seafood arancini are connected to their environment of origin: Sicily. Sicily is an island, which means it has great access to seafood. When there is a lot of seafood around, people tend to make use of it in their cooking. When I was in Sicily, I ate a lot of yummy "frutti di mare", from fish "meatballs", seafood pasta and shrimp-filled arancini.
Although the history of arancini is not clear, food historians do know that arancini were created around the 900sCE when Sicily was controlled by Arab rulers and not a part of Italy as we think about it today. In that way it is deeply connected to Italy, plus the people and cultures surrounding the nation today.