Seagen

Delicious fresh tuna bowls at quite a reasonable price. I was recommended to have the chef's select bowl and can continue that recommendation! You get quite a large helping of fish, and so the deluxe is really spoiling yourself. They also have half bowls as a great option if you can't decide.

Amazing tuna, melts in your mouth, fattiest tuna ever. Would definitely recommend the ultimate tuna bowl, they let us share one bug bowl because we were full from eating around the market. We lined up 20 minutes before the shop opened and got in without any trouble, would recommend you do the same. Strongly recommend

It is one of the best places to get tuna in Tsukiji and some of the best we've had in Japan. Their specialty is, of course, tuna, and with how good they are at it why would you want to order anything else.
They offer standard donburi bowls, and usually a special or two for the day. I usually get their two bowl option. They have an assorted sushi bowl and it's all good quality but the real star is the tuna, and while you might think 'oh, it's too much tuna' it's really not. It's just that good.
There are some people complaining about the sushi rice in the donburis and yes, they do use more vinegar than some places do in their sushi rice but their tuna is such a high quality with such a nice fat content that it's good for cutting through that fat. So I think there's nothing wrong with how they season their rice.
Get there early to try their zuke bowl otherwise it gets sold out very quickly, however, it's smaller version in the 'choose two' is usually still available at the end of the day.
Do expect a bit of a wait time when you get there, the longest we've waited so far to get in is about 20-30 minutes which is honestly nothing compared to some lines in Japan.