Rinse agar agar bar and tear into small pieces. Soak for approximately 30 minutes in cold water (or follow the package instruction).
Cut Tofu into small pieces. Add to large pot of water, bring to a boil (or microwave for 1 to 2 minutes. Caution: Tofu will be hot to touch after microwaving). Remove from heat and drain well. Blend in a food processor until texture becomes smooth.
Make dashi stock following the package instructions. Squeeze agar agar bar and add to dashi stock (if using agar agar flakes, just add to stock) and bring to a boil. Remove from heat and let sit until room temperature.
Add Tofu and crushed walnuts, honey, and lime juice to dashi agar agar mixture. Put into loaf pan and refrigerate until Tofu hardens.