This is pretty much what the tuna belly I got from the fisherman dude looked like. When I cut the first piece, I had a similar experience, mostly from my lack of experience I think, and also because I belatedly realized that given the fat content, I should have either chilled it well or partially frozen it for ease of slicing.
The second piece looked better.
Went looking for a pic, but I guess I forgot to take a pic of the whole piece, just the finished dish.
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Yes, the belly is the lower half, after the innards are taken out, so it is naturally a lot thinner than the upper portion.
Agree with what @Amandarama said – there’s a reason a lot of toro comes finely chopped (sometimes with daikon).
