This cultivar was listed on the MyHostas Database website. Originated in Japan, this non-registered cultivar is a sport of H. kikutii var. polyneuron.  It is a medium size hosta with narrow green foliage that has a white medial (center) variegation. Lavender flowers bloom from August into September.

Mikiko Lockwood in an article on The Hosta Library titled, A Little About Japanese Hosta Terms defines the term shironakafu or shiro nakafu as white-center(ed).