Originated in Japan, this non-registered cultivar is a sport of H. sieboldii.  It is a small size hosta which grows to about 9 inches in height with a spread of around 22 inches. The foliage is green with white medial (center) variegation and has thin substance.

Mikiko Lockwood in an article on The Hosta Library titled, A Little About Japanese Hosta Terms defines the term shirobuchi as white edge(d) and the term koba as small leaf, 'Koba Gibōshi' or H. sieboldii.