Danny Van Eechaute of Belgium registered this sport of H. 'Koryu' in 2004. It forms a medium size plant about 10 inches high with dark green leaves which have a lighter green medial (center) variegation. Pale purple flowers bloom in September. It varies from the mother plant by having smooth textured leaves.

Mikiko Lockwood in an article on The Hosta Library titled, A Little About Japanese Hosta Terms defines the term midori as green and the term koryu or Kouryu as a raised ridge along the center of a leaf.