After Disguising Herself as a Man and Entering Military Academy, She Can Never Escape

To raise the money for her comatose brother's medical bills after he was injured in a car accident, she takes a job entering a military academy in place of a rich second-generation heir. She thinks all she has to do is train hard, then leave with a huge payout when the heir no longer needs her. But she gradually realizes that her three roommates are watching her like hungry wolves, and even her brother, who had protected her for 17 years, is beginning to act strangely...