Aoba Festival is one of Sendai's Big Festivals, along with the Tanabata Festival, the Starlight Festival and the Jozenji-dori Jazz Festival. It has a history lasting hundreds of years. It takes place on a weekend in May and hosts dozens of performances and food stalls.
On the second day of the festival, they close two long stretches of road for the parade. For over three hours, wheeled floats, Suzume Odori (Sparrow Dance) groups, samurai and more make their way down Kotodai Road and Jozenji-dori. It's very popular, so you might want to get there early and reserve a good spot - it only happens once a year!
