An image forming apparatus includes an image rotation processor and an image combination unit. The image rotation processor is configured to: rotate the form image such that the direction of the upper edge of the document image on the first page matches a direction of an upper edge of a form image if the direction of the upper edge of the document image on the first page differs from the direction of the upper edge of the form image based on the form image data; and rotate a document image on each page of the second page and the subsequent pages such that the direction of the upper edge of the document image on the first page matches a direction of an upper edges of the document image on each page of the second page and the subsequent pages in a similar case.