Green tea and soba noodles are nutty firm noodles from Japan. The former are made from wheat with added powdered green tea, and the latter can be either a mixture of wheat and buckwheat or 100 per cent buckwheat. I prefer the mixed-grain soba noodle, as the pure buckwheat noodle can be quite brittle and almost crunchy.
The tofu here is the same type and cooked in much the same way as in the recipe. Mirin is Japanese rice wine used only for cooking