The fireworks over Ryogoku Bridge depicted in this uchiwa-e (rigid fan print) design by Hiroshige were a regular feature at Edo during the hot months of summer. They could be enjoyed from the bridge itself, from pleasure boats and restaurants on and along the banks of the Sumida river, or, as here, from the rooftops of distant houses. The summer season at Ryogoku officially opened on the 28th day of the fifth month with the staging of the kawabiraki or 'Opening the River' ceremony. From then until the early autumn it was thronged by visitors intent on taking in the cool of the evening, a custom known as yusuzumi.