Izuku Midoriya has been send back in time by accident because of one of Hatsume Babies but that wouldn't be bad as Izuku will meet the 7th user of OFA and both of them fall in love and defeat AFO.
When Inko dies in Quirk accident, the same Quirk sends four year old Izuku Midoriya back in time to the base of the Second and Third users. How will Second, Third, and Yoichi handle being forced to co-parent a toddler and fight All For One?