Finally tried it and I felt that it lacked chestnut taste and it just tasted like Tiramisu/Coffee.
Other flavours in the Hokkaido-Yo series.
Circle K Hokkaido-Yo Peach flavour
http://supersupergirl-food.blogspot.com/2012/07/circle-k-hokkaido-yo-peach-flavour.html
Circle K Hokkaido-Yo Original, Grape and Fuji apple flavours
http://supersupergirl-food.blogspot.hk/2012/05/circle-k-exclusive-hokkaido-yo.html
Circle K Hokkaido-Yo Sweet Purple potato
http://supersupergirl-food.blogspot.com/2013/03/hokkaidoyopurplepotato.html