Spy Classroom, Vol. 1 (manga)

Lily, known by her code name Flower Garden, aspires to become a master spy in a war-torn world. She is thrilled to join an elite squad that undertakes high-risk missions with a 90 percent mortality rate. However, she quickly discovers that the team consists entirely of academy washouts like herself. Despite their lack of experience, each member has the potential to make a significant impact. Under the guidance of master spy Klaus, they must work together to prove their worth and take on impossible challenges.