Translating common phrases from Japanese can sometimes be confusing. Not everything works as well (or directly) in another language. It'd be easy to make a 'Lost In Translation' joke here, but there are plenty of sayings that make you wonder. I'll give you an example:
Now, that ('tofu no kado ni atama wo butsukete shine') literally means: 'go bash your head on the corner of a block of tofu and die'. It's the Japanese equivalent of 'go take a long walk off a short plank'. Or one of the ruder versions, if you use those..
This is an unusual one for several reasons.
First off, it's pretty difficult to hurt yourself on tofu, whether it's been cooked or not. I don't know if any of you've ever tried. (I sure haven't.) Even if you fry it for a while, that tofu's still going to have a soft and squishy consistency underneath. Bashing any part of yourself on any part of the tofu is a tall order.
And if we're going to go with the corner of the block, then why bash your head on it? Wouldn't trying to take your own eye out on a pointy tofu corner do more damage? I don't think it's possible to give yourself a lobotomy with a soy-based food product - and I'm not encouraging anybody to try.
All of this is without even covering the effort it would take to draw blood like that, let alone mortally wound yourself.
It reminds me of 'The Horribly Slow Murderer With The Extremely Inefficient Weapon' video on YouTube. (Fair warning, probably NSFW. Contains a lot of spoons.)
But hey, maybe that's the whole point. It wouldn't be a quick or simple way to inflict damage. The person who tells you to connect your head with some pointy tofu probably wants you to suffer. For your eventual death by coagulated soy milk to be drawn out, uncomfortable, and kinda humiliating.
So in this case, it's the intention that translates better than the actual words. I know tofu's high in iron, but not high enough to cause that much damage in a single hit.