Tenma is a man of average build with middle-parted black hair, brown eyes, and tan skin. At the start of the series, his hair is kept short and he is usually clean-shaven, but as the story progresses, his hair grows out to the point where it reaches his shoulders, and he is often seen with a stubble.

L is a very slim, pale, tall young man with messy neck-length black hair and black eyes. One of his most noticeable features is the shadow below each of his eyes, a result of him being an insomniac