My Sister's Duty

Dong-U, who happened to find the secret of his squad leader is spending a hellish day because of it. Jeong-Yeon, the younger sister learns of her brother’s suffering through his diary. To protect her brother whom she loves more than anyone else, Jeong-Yeon visits Jin-Ho, the squad leader…

“Oppa… I’ll protect you this time.”

(Source: TOPTOON, translated)