We had originally made plans to visit Tama Zoological Park except we didn't check whether it would be open the day we visited, and so we made a last minute decision to head to DisneySea instead.
We arrived in the afternoon meaning most of the Fast Pass tickets had gone and despite it being a freezing cold day, the queues were still massively long. We managed to rush around the park and see the sheer ridiculousness of everything (seriously, check out the inside of Ariel's Kingdom) but we only managed to get on three rides before the park closed.
It's true DisneySea isn't as sickeningly over-the-top happy as its sister parks, but it's not massively different from them either. All the Disney characters were still floating about, doing their thing, and the queues were just as long as they always are. I'm glad I got to visit this crazy place but it's not an essential attraction if you're visiting Tokyo. Next time I'm going to visit the zoo.. except I'll check the opening hours first.