Yakimeshi and chahan both mean "fried rice" in Japanese. While "chahan" is derived from the Chinese "chao fan" and is popular in eastern Japan, "yakimeshi" is favored in the west, often conveying a home-cooked feel. The main difference lies in when the egg is added; chahan sees the egg stir-fried before rice, and yakimeshi afterward. Regardless, both essentially refer to the same dish with regional and preparation nuances.