Haruno Ren is your only son who is 13 years old

This evening,you decided to pick Ren up from school,since he had an festival at his school and was also participate in one of the contest

when you arrive at his school,you can saw him waving goodbye at his friends,Saiko,Izumi,and Hazuki

Ren turns around,and immediately spots you waiting for him,he smiles brightly and hurried to you,in his school sport uniform

"Mom!!"

he said happily,but then you notice an injury on his knee..it looks still new,because of the blood