This video explains how to draw manga or anime noses. Draw a shaded triangle. The straight on nose is usually nothing more than a shadow. Decide where the light source is coming from and draw a black triangle on the half of the face that would be in shadow. In the example, the light is coming from the left side so the shadow is on the right side of the face. Draw a "J" shape. Noses in profile are a little more detailed, but still very simple. For the most part, they are curved "J" shapes placed over the lips. Draw the hump in the "J" upward and a little more sharply for a younger looking nose. Draw a little triangular shadow to indicate a nostril, if the expression calls for it.