Teenage Mercenary MANGA

At the tender age of eight, Ijin Yu was tragically the sole survivor of a horrific airplane crash in a foreign, war-torn land. To survive in this brutal environment, he was forced to become a child mercenary, undergoing years of grueling, life-threatening combat training and participating in countless deadly missions. After ten years of living as a highly lethal ghost in the underworld, he finally manages to escape and returns to his home country of South Korea to reunite with his remaining family - his grandfather and younger sister, Dayun. Eager to live a peaceful, normal life, Ijin enrolls in high school. However, he quickly discovers that the school is a different kind of battlefield, plagued by ruthless bullies and corrupt, wealthy students who prey on the weak. When his beloved sister becomes a target, Ijin's deeply ingrained mercenary instincts resurface. Utilizing his overwhelmingly superior combat skills, tactical genius, and lethal precision, he systematically dismantles anyone who threatens his family's peace. 'Teenage Mercenary' (also known as Mercenary Enrollment) is a phenomenal action webtoon that brilliantly contrasts the mundanity of school life with breathtakingly intense, professional-grade combat.