A few weeks ago, I had a chance to meet up with a few friends from ICE who were in Tokyo for work, and another friend from the Kennel who happened to be vacationing in Tokyo at the same time. It was great getting to hang out; I definitely have moments of LA-homesickness (to differentiate from homesickness for my actual hometown), and hanging out with my former Naughty Dog coworkers definitely cured it that weekend.
On one of the nights, we had dinner at Ninja Akasaka, a ninja-themed restaurant located in Chiyoda-ku. It is built like a ninja fortress, a dimly-lit labyrinth of winding hallways, secret doors, and crumbling bridges. Even the entrance to the restaurant itself is somewhat concealed.
Upon arrival, we were greeted by a ninja (of course) and brought inside in separate groups of five, as the narrow, winding corridors could only accommodate a few people at a time.
The “fortress” ambiance was quite convincing. The cave-like walls, the torch lighting and the maze-like layout of the place really did make you feel like you were transported back to the Sengoku period, only an alternate-reality Sengoku period in which all the ninjas are happy and smiling and are more concerned with serving you really amazing food, rather than being immersed in endless war and political chaos.
Anyway, after our treacherous journey through the restaurant, we were all finally reunited with our group in a private dining room. Interestingly, the singer Bruno Mars had also, at one point, dined in the very same room, as evidenced by this scribble on the wall:

Clearly, this alternate-reality Sengoku period is one in which pop singers vandalized ninja property.
We each opted for the Yamato Spirit Course, an 11-course tasting menu, which included some ninja-themed items (e.g. Shuriken star blades grissini) and some creative takes on familiar dishes (e.g. Ninja-style cream puff, a savoury version of a cream puff).

Ninja washroom! Because the restaurant is constructed like a maze, you need to ask a server to escort you to the washroom so you don’t get lost.
After we cleaned off our plates, we were treated to a post-dinner ninja magic show, which consisted of standard card and coin tricks, but the fact that the ninja magician performed them while seated with us at our table was pretty neat.

One of the playing cards, touched by ninja magic! (We weren’t allowed to film or photograph the magic show, but no one said anything about documenting the evidence afterwards.)
Overall, I very much enjoyed Ninja Akasaka (and even moreso because I didn’t have to pay :P). Tokyo is full of theme restaurants, and this one was pretty elaborate and well executed — I recommend going at least once, and definitely with a group of good friends to share in the experience.