Itoshi rei was her name. Yes indeed She was the younger sister of the so famous New Generation World's 11, itoshi sae. Her twin was itoshi rin who was also her younger brother (she was born a day before him and would never shut up about it). This story happens when they were younger children in elementary school. Characters (other than rei ofc) belong to Muneyuki Kaneshiro author of blue lock. Also story cover was done by me :)