This non-registered hosta from
Japan is a form of H. 'Sagae'. It
becomes a medium size hosta with viridescent foliage that changes from gold to green as the
season progresses. Pale lavender flowers bloom from mid-July
The Hostapedia by Mark Zilis (2009), "H. 'Gold Sagae' = H. 'Ogon Sagae'.
is a Japanese cultivar similar to H. 'Sagae' with yellow, not variegated
leaves. It probably is a seedling or sport of the latter."
Mikiko Lockwood in an article on The Hosta Library titled,
A Little About Japanese Hosta Terms defines the term ogon or oogon
as gold or yellow and the term ogon or oogon as gold or yellow.