Sushi, in particular, Japanese places in London are quite a few. However, finding quality places is fairly limited. YoSushi! is one of the cheapest places around lacking in much freshness of the fish and cannot in all honesty be classed as a Japanese takeaway. One of the best places I find in London is Atariya where the fish is just deliciously fresh and tender on rice. The sushi quality is splendid. They can be found mostly in north side of London and provide for both takeaway and eating in options. They have one main branch situated in central London. Atariya also provides a wide selection of fish and other options.