[odonata]

Ueno park is a must do. You can fit in Akiba as it is just down the road.
You also have Ameco market which is always buzzing and just a short stroll from the park.

You could get a train to Akiba have a look around then walk North keeping on the right side of the road. Take a right turn anywhere and then a left after one to five streets, your choice. You will hit Ameco market which you can spend many hours in and out of the many shops.
head north again and you will hit Ueno station. Head to the left of the station and you will find the park.