Purchase a ticket and join the crowds at a game at Sun Arena. If there's nothing scheduled while you're in town, you might like to check if there's a guided tour of the grounds.
This Futami sporting facility is a good place to kick off your day of sightseeing. There's lots to discover close by, like Ise Grand Shrine, Toba Aquarium, and Okage Row. Wander around at your leisure at Sun Arena before hitting up these other fine sights.