This seedling of H. 'Yakushima Mizu' was registered by Steve Chamberlain of New York in 2003. A small size plant only 8 inches high by 15 inches wide, it forms a dense mound and produces pale purple flowers in July.

The Book of Little Hostasby Kathy and Michael Shadrack (2010) says: "Extremely vigorous and will grow quickly almost anywhere. Will take a little sun. Multiple dark flowers held on very tall scapes."

Mikiko Lockwood in an article on The Hosta Library titled, A Little About Japanese Hosta Terms defines the term mizu as water, 'Mizu Gibōshi' or H. longissima.