If you're in the Kansai area, I recommend that you check out Harbourland in Kobe for a great night view!
You can do some sightseeing around Kobe, maybe in Kitano - one of the oldest foreigner settlement in Japan - or in Motomachi Chinatown - one of the largest Chinatowns in Japan. Or, you can do a bunch of shopping around Harborland and, if you're traveling with children, there's the Anpanman Children's Museum and a ferris wheel.
For shopping, there's Mosaic Mall, Umie (North and South Mall), and the Promena shopping center. The atmosphere of Mosaic is very nice, even if you just walk around! It is an open mall atmosphere and there are a ton of stores selling a wide variety of items. Unlike the Umie North and South Malls, most of the stores in this mall appear to be Japanese-style rather than imported American and European brands. The Umie complex, for example, has Old Navy and H&M. The Umie Mall has a large electronics store, bookstore, UNIQLO, Toys R Us, Babies R Us, and a home furnishing store. These stores seem more family-oriented.
The Mosaic Mall has a ton of stores that sell character goods including: Kewpie Shop, Sanrio, Snoopy, Madeleine, The mall also had a bunch of stores with Kobe merchandise and Kobe sweets. The clothing and accessory stores in Mosaic seem to be more aimed at younger audiences. There are also a lot of options for snacks and meals. A few of the cafes has a very good view of the harbor. You will also see many many many couples. This is apparently a very popular date course destination for young couples in the Kansai area.
To access this area, you can alight at JR Kobe Station. It's also a short walk from Motomachi and it is walkable from Sannomiya.
There is a ferris wheel next to the Mosaic Mall. It is very colorful. The patterns of lights change all the time and it is fun to watch from the opposite side of the port, across from Mosaic. You can access the opposite site by following the path around past the Hotel and the Naka Pier. You will find yourself next to the Kobe Port Tower. You can tour the tower for 600Yen and it is from 9AM until 8PM. If you continue walking, you will find yourself in Meriken Park.