Katsuo (Bonito) – Bonito is seasonal during the winter when they swim south from northern Japan towards the south Pacific. They are best when fished individually with a pole and not with a net. The reason for this is that they have very strong muscles, and they can ruin their flesh (by muscle fatigue) by trying to escape the net. Bonito is one of the earliest ingredients of the Edo style sushi. They have the highest fat content beginning in fall, which is their season. During the Edo period, it was trendy to eat bonito in the early summer to enjoy the lean taste, and wait for them to become plump during the fall and enjoy them again. This had more to do with enjoying the seasonal changes, but the Edo culture was known for their busy lifestyle, and some other regions in Japan ridiculed them for eating the bonito to early.