First good news: the location. Nikkei is located in Belém, near river Tejo, which probably will already be a part of your journey. You will find three restaurants in that same place, all part of the Vela Latina group. As soon as you enter Nikkey, you know you'll have a good time.
The doses are not large. Consider ordering the tempura as a complement: it is mind-blowing and fills your stomach.
Second good news: the experience. The Nikkei has good taste in interior design and an exquisite environment. Like any fine restaurant, it doesn't have much light indoors, which brings you a sense of calm and comfort. It also has a separate room for those who want to sit more privately. Outside it has two garden areas with little lights shining in the evenings. Menu-wise, the restaurant has a wide choice of dishes, from starters to chef-chosen plates or smaller doses of sushi. And with this comes the inevitable not-so-good news: the price. Of course, the luxury also had to reach the wallet. You do not pay less than 80€ per couple — or at least if you want to make sure you won't feel hungry an hour later.
Shrimp tempura with slightly spicy sauce, mix greens and avocado
Seasoned with Peruvian aji amarillo and truffle
If you're a group of people
It's indeed a revelation the mixture of the latin spices, sweets and sours with the simplicity of fresh fish and other japanese treats. Try to order as much variety as you can to get to know the real deal and let yourself be surprised by Nikkei's dishes.