This has been mentioned in a few posts but I thought it more than merited a thread of its own.
Our third visit, chosen by my son as his off-to-uni farewell dinner, which is high praise indeed.
It's just behind the Strand, by the Liver Building. Lovely little restaurant, all wood and slate, with outdoor tables and decking for sunnier times.
We started off with a mixed seaweed salad and some exemplary katsu pork (the kari age, gyoza and tempura have all been good in the past too).
Then a great value for £9 sashimi set including tuna, salmon, sweet shrimp, squid and snapper; nigiri with seared tuna/bream/salmon with various toppings and marinades; temaki with eel/cucumber and soft shell crab; unagi donburi, very generous with the eel, lovely sweet eel sauce, and moreish pickles.
There's a wide selection of sochu and sake, and my son loves the Japanese whisky.
Charming service. The sushi can be a bit slow as they only have one sushi chef for about 40 covers, but worth the wait.
We paid £60 for the above plus drinks. Highly recommended.