Unexpectedly, in the Last Days, What Does It Mean to Depend on Each Other for Life and Death?

There are always people in this world who say similar oaths, but their feelings are inseparable, adding another layer to this complicated world. They lived together in a military compound since they were young, and they were said to be lifelong brothers. When they grew up, one became a teacher, and the other inherited his father's legacy and went to the military camp. Unpredictably, they fell in love with the same girl by accident.