Squid Sashimi イカ刺身
A Japanese restaurant Ika-center イカセンター specializes in fresh squid sashimi.
Some squids are kept alive in the tank of the restaurant. Immediately after the customer orders, it is sliced as sashimi.

This is called Iki-ika-no-sugata-zukuri 活イカの姿造り. You need to order the whole body if you want this.
Squid Sashimi イカ刺身
Squid arms sashimi
The squid arms are still moving a bit. Eat the moving squid arms!
* The arms are included with Iki-ika-no-sugata-zukuri 活イカの姿造り.
When I went there, it was 1980 yen. The prices are depend on the squids. Sometimes it is more expensive though.
Squid Sashimi イカ刺身
There are some tanks in the restaurant.
Squid Sashimi イカ刺身
Name
Ika-center イカセンター

Branch
Shinjuku-souhonten 新宿総本店 in Tokyo

Google Maps
* The entrance is located on the 5F. However, they also have another floor on the 4F.

Official website (in Japanese)
http://www.ikacenter.com

Another website (in Japanese)
https://r.gnavi.co.jp/a640602/

Note
Squids in the tanks are often sold out or no stock because of purchasing from a fish market and this restaurant is really popular.

Cover charge is 300 yen per person.
Prices on the menu are not including 8% tax.

To be honest,
I definitely recommend Ueno 上野 branch more than Shinjuku 新宿 branch above.

Because Ueno 上野 branch started their business just several weeks ago, it is still unknown to many people. For now, you probably don’t need to make a reservation.
Shinjuku 新宿 branch is too popular to make a reservation, and their squid sashimi is often sold out quickly.

Ueno 上野 branch’s rooms are more spacious, comfortable and newer.
Their official website does not show anything about Ueno 上野 branch, yet.
Ueno 上野 branch in Tokyo is the best choice now!
Check it out!
https://r.gnavi.co.jp/3257vbhf0000/map/ (in Japanese)

Google Maps