Madara reveals himself to be Naruto's grandfather. He infused both his cells and Hashirama's cells into Naruto. Naruto becomes strong as a result, awakening the sharingan and later the Rinnegan.
Naruto is Madara's Grandson. Madara will start to train him at the age of 5. But a Certain Goddess has set her Eyes on the Kid and wants him to be hers.