What wonderful water irises!

The Water Iris Festival has a long history, taking place for the last 70 years or so, and makes the Yatsuhashi Water Iris Garden venue the target of numerous sightseers from around Japan each year. The garden's water iris blossoms are available to view throughout the festival period, but meet their peak bloom during the Golden Week consecutive holiday.
The water irises of Chiryu City's Yatsuhashi area became famous for their role in a poem written by Heian period-poet Ariwara no Narihira, from the Tales of Ise story, when he came to Yatsuhashi and composed a poem famously making a pun of the Japanese word for "water iris (kakitsubata)" in haiku fashion. The irises' home of Yatsuhashi Water Iris Garden is an expansive 13,000 m² with 16 ponds (5,000 m²). Water irises are the flower of Aichi Prefecture as well as the city of Chiryu, and enjoy a warm welcome from its residents. In fact, the water irises on the 5,000 yen bill are said to be the Yatsuhashi water irises.