As someone who has purchased many, many, many plastic clamshells of questionable grocery store "sushi" over the years (mostly prior to having the world's most depressing dinner off my coffee table and/or as an excuse for drinking two bottles of sake in one sitting at home), I feel qualified to make the following statement: You need to stop buying grocery store sushi at lunch. Stop right now.
Rarely does one have a stronger aftertaste of regret than after consuming a California roll smeared with horseradish paste dyed green, its crab-with-a-K filling leaving an unpleasant slick of fake brine across your tongue as the gummy rice sticks like Elmer's craft glue to your molars.
There's nothing quite as depressing as paying $15 for a plastic tub of salmon and tuna that taste nothing like fish, but faintly of sterilized air. And let us not discuss "tuna scrape," which is the slightly more offensive version of pink slime and far more likely to kill you.
You get the sashimi bento box above at Kata Robata for only $13 at lunch every day. This is far less than you'll pay for "sushi" or "sashimi" at the grocery store, and it is far less likely to leave you questioning the rest of your life choices (like why you can't return Redbox videos for at least two weeks, or why you're 32 years old and still have a hard time remembering to pay your Comcast bill, or why you need so many cats).
Today, you will get one thing right in your life. Today you will go to Kata Robata and sit in its calm, elegant dining room like a fully-functioning adult and you will order the sashimi bento box and perhaps a mug of green tea (for the antioxidants!), and you will glory in chef Hori-san's beautifully presented lunch when it hits your table.
You will notice real shiso leaves as garnish instead of the plastic grass that's nearly identical to the crap sold as Easter basket stuffing at Walmart. You will watch the wiggle of bonito flakes atop a warm pile of agedashi tofu, and eat seaweed salad that doesn't taste like the interior wall of a recently emptied fish tank. You will enjoy salmon and tuna and scallops that taste like actual fish from an actual ocean. You will wonder why you ever slunk over to the grocery store at lunch and overpaid for underwhelming chum. And for at least one brief hour, you will be triumphant.