Cut the tofu into bite-sized pieces.
Drain the oil from the canned tuna and set aside.
Finely chop the kimchi.
Heat cooking oil in a pan and stir-fry the kimchi.
Once the kimchi is somewhat cooked, add the tuna and stir-fry together.
Add the tofu and gently mix while stir-frying.
Season with soy sauce, sugar, and pepper.
Serve the stir-fried mixture over rice to finish.