Many times when you are going through manufacturers' or retailers' websites you will encounter tires recommended for the EX250 listed as Scooter Tires. Be not alarmed. Even though, to many uninformed people, scooters are perceived as being 'less' than true motorcycles, it's not as though the tiremakers are going to say "Oh, it's just for a scooter. Who cares?"
In reality, the 250 is in the same weight/performance area as many modern scooters. Many of the new scoots weigh more and have larger-displacement engines than our bikes, so it won't hurt anything to put a scooter tire on a Ninja. Scooter riders have a right to performance, too. Just make sure the load range and speed ratings are equal to your intended use. They almost always are.
If it weren't for scooters, we wouldn't have as many choices in tires as we do. In fact, our beloved MT75 used to be on Pirelli's scooter page, until they figured out that a lot of them were being sold to Ninja and Buell Blast owners.