today tuna is considered as the pinnacle of fine sushi item but he was not until the early 19th century the Japanese people tried to eat tuna and they qualified tuna for an official term of disparagement des econo tuna Toro the Patty belly part of tuna which is now one of the most expensive and quality sushi item has been considered as the most disgusting part historically tuna has been called shibi which is the same final session in Japanese ads for days because it loses its freshness pretty quickly within a couple of days and is associated with the World XI which means death this was a part of the reason why Japanese people tried to avoid eating tuna until one of the street vendors catering to the lower classes started marinating tuna in soy sauce in order to enhance its preservation quality and masked the inherent flavor thanks to the refrigeration technology tuna is now widely distributed with its freshness we can enjoy a big haul tuna in sashimi style without getting it rotten and it is not necessary to marinate tuna for preservation purpose however because even today handful sushi restaurants serve marinated tuna DK Maduro as a traditional Adama style when you eat marinated tuna you reminded of the long history of sushi prepare soy sauce mirin and cooking sake at one to one to one ratio and combine them in a medium bowl boyeur it quickly of a stove to evaporate alcohol and make soy sauce taste milder then go it down slice a block of tuna into pieces dip them in the marinade sauce and leave them for about five minutes in the fridge alternatively you can also dip a whole tuna blood into the sauce if that's the case maybe for about 30 minutes the length of marinating time is up to your preference but the longer you keep it in the sauce the saltier the taste will be and texture be harder scoop them out of the sauce and dried them with paper towel make it into nigiri style and garnish with green onion and sesame seeds you