Soak 8 bamboo skewers in water for at least 30 minutes.
Make 4 rows of 3 scallops each on cutting board. Thread 2 skewers through each row of scallops. (Using 2 skewers keeps the scallops from slipping on the skewers during cooking.) Set aside.
For the marinade, whisk miso and water together in small bowl until smooth. Transfer marinade to shallow container or plate and set the scallop skewers in marinade. Cover with plastic wrap and marinate, refrigerated, 1 to 2 hours, turning once.
For the sauce, place beans and garlic in a small saucepan (with just enough water to cover) over medium heat and simmer for 7 minutes. Transfer mixture to a blender. Add tofu and lemon juice and blend until smooth. (The sauce might appear a little thick, depending on the beans. Thin if necessary with a little warm water.) Season with salt and pepper; keep warm.
For the relish, heat two tablespoons of grapeseed oil over medium heat in small skillet until oil is hot. Add tomatoes and cook until tomato juices evaporate and the relish looks like a chunky sauce. Remove pan from heat and immediately stir in green onions. Season with salt and pepper; keep warm.
To prepare scallops: Heat one tablespoon of grapeseed oil in a large non-stick sauté pan over medium high heat until hot. Remove the scallops from the marinade and wipe any excess miso from the scallop skewers. Add the scallop skewers to the hot pan. Cook two minutes on each side or until nicely browned. Spoon some of the edamame sauce onto the center of four warmed plates and spread with the back of the spoon. Set the skewers over the sauce and top with the relish.