Originated by Toshiro Shimizu of Japan but registered in 2009 by Kevin Walek (Hosta Registrar) on his behalf, this small size (10 inches high by 18 inches wide) cultivar is a form of H. longipes. The green foliage has creamy yellow to white streaked variegation. Its leaves are flat, lanceolate and slightly shiny on top. Tubular flowers bloom in September.

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