Board Thread:Chapter and Episode Discussions/@comment-4704473-20141106114903/@comment-1512913-20141107212750

In the ninja world, the children enter the academy at different ages and graduate according to their prowess. So it's possible for a 5 years old to enter the Academy and graduate in just 1 year, while some other kid may enter as 10 years old and graduate at 50 for all I could care.