Mars Shinshu Iwai Tradition is a blended Japanese whisky produced at the Mars Shinshu Distillery, operated by the Hombo family and located at 798 meters elevation in the Nagano mountain range — the highest whisky distillery in Japan. The distillery's high-altitude location was chosen for its moderate humidity and access to high-quality mountain water, both of which contribute to the whisky's character.

This expression is a blend of single malt and grain whiskies aged in a combination of ex-bourbon, ex-sherry, and ex-wine casks, giving it a layered complexity. The whisky is named in honor of Kiichiro Iwai, known as "The Silent Pioneer of Japanese Whisky" and the mentor of Masataka Taketsuru, the founder of Nikka Whisky. Bottled at 40% ABV with no age statement, Iwai Tradition delivers notes of ripe cherry, honey-toffee, ginger spice, briny peat, creamy malt, and smoked almonds with a rich, full-bodied character.