Tsunahachi has apparently been around since 1923, a stalwart of tempura for a long long time. We were recommended this place from a friend of my friend - and we trooped there after our first choice (Yoroiniku) was fully booked.
And it was not a bad meal! Light, fluffy tempura batter, coupled with fresh ingredients. You could really taste the sea flavours of the prawns, and the squid was done perfectly in texture.
A special shout-out goes to the miso soup which was one of the most flavourful I've ever drunk - it was full of small clams.
Overall, a great tempura joint and pretty value for money. About 3000 yen all in.