Bob Kuk of Kuk's Forest in Ohio registered this sport of a plant that resulted from the cross of H. 'Gold Regal' × a gold H. 'Tokudama' seedling in 1999. The mound grows into a large size hosta about 22 inches high and 30 inches wide with wavy, moderately corrugated, somewhat unruly foliage. Its lavender flowers start to bloom in late July followed by viable seeds.

According to The Hostapedia by Mark Zilis (2009), "The ratio between mound height and mound width for the average hosta is 1 to 2½. Vase-shaped plants often fall into a 1 to 2 or 1 to 2.3 range. Amazingly the mound height to width ratio for 'Unforgettable' is 1 to 1.4...combination of a distinctly upright habit with striking gold-margined variegation and an unruly character gives 'Unforgettable' a high level of distinction."

The New Encyclopedia of Hostas by Diana Grenfell (2009) states: "Origin: Sport of H. 'Gold Regal' × H. 'Golden Medallion'...The contrast between the marginal variegation and the darker leaf blade is exceptionally striking. A superb introduction...The tall flower scapes, inherited from the H. 'Gold Regal' parent, make this hosta more attractive than many others with H. 'Tokudama' parentage."