Time Out says
Yukata-clad spectators crowd the streets of Harajuku and Aoyama during the annual Jingu Gaien Fireworks, a display that ranks alongside the Sumida River Fireworks as one of Tokyo's top summer festivals. The cluster of sports stadiums to the south of Sendagaya Station offer the best vantage points, albeit at a significant premium. Expect to pay between ¥3,000 and ¥9,000 for a seat, with the priciest ones at the main stage of the event: Meiji Jingu Stadium. Tickets includes a program of J-pop performances in the run-up to the fireworks themselves. Alternatively, just wander around the surrounding area until you find somewhere you can see the action for free.