This non-registered cultivar from Japan is probably out of the species H. sieboldii. It grows to 15 inches in height with a width of 35 inches. The leaves are narrowly ovate to elliptic, slightly shiny on the bottom and have thin substance. Its medium purple flowers bloom in August.

According to The Hostapedia by Mark Zilis (2009), "This plant has been listed under so many names it is hard to remember them all...Another possible name might be 'Ginko Craig', which 'Mr Asami Improved' closely resembles in foliage and flower (in both juvenile and mature forms)." 

Mikiko Lockwood in an article on The Hosta Library titled, A Little About Japanese Hosta Terms defines the term nishiki as brocade (rich-colored woven fabric) i.e. something colorful and beautiful.

We don't know for sure but this could be named for Hisatoyo Asami who was once credited with originating H. 'Chōkō Nishiki' which was previously known as H. 'On Stage'.