If you are into "Midnight Diner"-esque night experience but not into a crowded Shinjuku scale, then this is a good alternative. Smaller and much more laid back.
This mountain is known as one of the top one hundred famous mountains in Japan. And is one of the highest mountains in the Tokyo area. I went mountaineering at the end of last autumn, and felt cold at the summit. The views changed as winds pushed away thick clouds, and I felt that winter was just around the corner. Scenery is breathtaking. It is recommended as a mountain comparatively easy to climb.
Contemporary art museum of Tokyo. I had the chance to attend to 3 cool exhibitions. Huge rooms, nice scenography, good sound (saw Dumb Type collective/Ryoji Ikeda installations).
Good restaurant too!
The Tokyo Tower is a symbol of Tokyo, and also it's sending electromagnetic waves such as television waves. In other words, if it wasn't for this tower Japan wouldn't be enlightened with important news and truth from the outside world. At 332.5 metres, it is the second tallest artificial structure in Japan.