An article by W. George Schmid in The Hosta Journal  (1996 Vol. 27 No. 2) states that this is an "old" incorrect name for Hosta clavata 'Urajiro Musashino'.

Mikiko Lockwood in an article on The Hosta Library titled, A Little About Japanese Hosta Terms defines the term aoba as green leaf and the term urajiro as white-backed or white underside.