What an interesting list of ingredients. I didn't have grapefruit to garnish this with, but for some reason there's a bitterness in here that's a bit reminiscent of the pith of a citrus peel, which I didn't like. Still though I enjoyed this drink, but I may not return to it soon.
I used Nikka Whiskey, which has a fruity nose and a smoky finish, and apple vermouth. Over all interesting but I wouldn't recommend. Maybe the other versions would work better.
I used the Japanese Hibiki Harmony, which has distant fruity and citrus notes. Strongly recommend twisting thick grapefruit zest. Love it, this is a shiny newcomer.
The Japanese whiskey (I used Suntory) and large proportion of bianco vermouth set this apart from other whiskey drinks. No grapefruit zest so I used orange. Highly recommended.