Takasaki City is 50 min from Tokyo. The city center has many shops & hotels and is a convenient travel hub. Takasaki city also includes Mt. Haruna and Lake Haruna, 40 min drive away.
Kinugawa Onsen and Kawaji Onsen are popular onsen (hot spring) areas 2hours from Tokyo. Why not relax in a hot spring at one of the many Ryokans with hot springs?
Maebashi City is 70 min from Tokyo. It's an exciting art and nature city, including nearby Mt. Akagi, Lake Onuma, and more. It's also a good base to use to travel around the region.