A gutter cover inside miter to be used with both open valley and closed valley roof miters, where the gutter cover inside miter is formed by coupling two primary member having a stem, legs, a tapered trough, a diverter and a plurality of draining and guide vents oriented to accommodate a variety of water flows. The gutter cover inside miter is also used with an underlying gutter cover as a system to improve the functionality of the gutter cover.