3rd Floor of Omotesando Hills. Omotesando station is easiest access.
Plum ramen? Not just any plum, but some nice 梅干し. That's sour, fermented plums people. You usually find it in rice balls or shoved in your face by a smirking bar master at a back alley drinkery. But here it's mixed into a simple salt broth ramen. The combination is wonderful...if you like 梅干し. Which I do.
By the way, this place is up-freaking-scale. It's in the elite Omotesando Hills shopping complex. You came here at dinner time? Sorry, budget minders need to stick to lunch time. At dinner, there is some sort of ramen course menu for 5500 yen, about $55. To say that homey don't play that would be the understatement of the week. Lunch was 1500 yen, which although it's about double what a normal bowl costs at any other place, is doable. Part of the allure of ramen in Japan is it's cheap price. For $55, I could eat steak, or fugu, or better yet, I could eat ramen every day for a week.
Official Site Here
More Sop Info Here
MIST is featured at the #2 spot in this video: