From the Burpple community

It could only be Saba (Japanese Mackerel) Especially this wonderful piece of Saba サバ Nigiri Sushi (💴¥250/💵S$3.10 for A Pair?!) from Harukoma (春駒 支店) in Osaka, Japan. 🍣

Harukoma (春駒 支店) serves authentic nigiri sushi at a very affordable price. It's cheap & it's good. God it's so good that I went back twice. Always crowded with locals, that to be is a good sign. 🍶

ACAMASTIPS💮: Please (For Meiji's sake) Do Not add additional Shoyu しょうゆ (Soy Sauce) to your Nigiri Sushi. The Chef normally will Marinate your Nigiri Sushi with the right amount of Wasabi わさび , Shoyu or even Sea Salt & various other toppings that Compliments well with the Neta ネタ(Sashimi) 🎏

Definitely Do Not Mix Wasabi & Shoyu Together, its disrespectful towards the Chef (implying that his sushi is so bad that you need to mask the Flavours)
Plus it's a Sin, well according to my Sushi Bible. 🖖🏻