Hakodate has a tram network. You can use it to get to the major sightseeing spots of Yunokawa, Goryokaku, the Morning Market, the Bay Area, Motomachi, and Mt. Hakodate Ropeway.
A tram fare is typically between 210 to 260 yen for adults. You pay it when you get off. At 600 yen, the One-Day Pass is worthwhile if you plan on taking three or more trips in a day.
One-Day Passes are sold at some hotels and at the information center at Hakodate Station. You can also buy them from the driver before you alight. The pass comes with an illustrated route map with some English descriptions.