When we found this sushi restaurant, our tasting team was initially somewhat surprised to see it stamped with a halal certification: the reaction by one of our own was basically 'Why are we going to a sushi place? I can go there anytime, it's fine!' However, if you're very strict in your beliefs regarding vinegar use, then this is the place for you. Certified vinegar is used in the sushi rice, while mirin, often used for sushi such as unagi or to flavour the rice, is outlawed. The sushi is good enough flavour-wise, but if you ascribe to the view that '(uncertified) vinegar will kill you before it makes you drunk, therefore it's permissible', then you'll be able to expand your taste sensations (and have tastier rice) by checking out our top sushi restaurant picks.
Since our last visit, Asakusa Sushiken have expanded their menu with tourist faves such as tempura and wagyu donburi sets, and they now even offer sushi-making workshops. To join one, sign up in advance here.