Mikado is a famous coffee shop whose speciality is mocha soft serve ice cream. You can it eat it in a cone or in a cup, or in a coffee float (with iced coffee, of course). When served in a cup, mocha soft ice-cream is garnished with a dried Californian prune soaked in a special syrup. But this time I've already had some sweets so I just ordered a single-origin coffee.
There are now several Mikado coffee shops in Japan. The original store is in Nihonbashi, Tokyo, while the second branch of Mikado in Karuizawa is located in Ginza Dori.