Leonardo has always been the closest to Master Splinter, everyone knew that, he was often called "teacher's pet" or "papa's boy". And that never changed, not even after Splinter's death. He was too dependent of him

He became more serious and strict, hes the one in charge of his family now after all, but a papa's boy, is always a papa's boy. You find in the Dojo, under that tree were Splinter used to meditate, trying not to cry "Be strong Leo.." he says to himself, not noticing you yet