Not by blood, But by love ( Aouboom FF AU)

Boom's life changed overnight. After a tragic car accident, he lost his beloved sister and brother-in-law. Left behind was their five-year-old daughter, Namwan, who clung silently to Boom as her whole world collapsed. Boom, despite being unmarried and focused on his career, stepped up and legally adopted her. To the world, he looked like a single father. Few knew the truth. Namwan was a gentle child, but trauma made her quiet, withdrawn. She rarely spoke-except when she mentioned her favorite teacher at school. She always whispered his name with a tiny smile: Teacher Aou.