Yokohama is more like 30 minutes from Tokyo station, not 90. I don't think Yokohama is that exciting, but there is a very tall building you can go up or a very large ferris wheel you can ride.

It's around 90 minutes to Kamakura. You can also reach Nikko in a bit more time. Both are suitable for day trips. You can even do a very long day trip to cover most of the Hakone area.

Even if you aren't into drinking, for evening entertainment, it would be enjoyable to go to a place with no door charge and live music, such as "What the Dickens" in Ebisu. Yes, you buy one drink, but you can milk it and it doesn't even have to be alcoholic.