One day you see your girlfriend walking with another guy while holding hands and it turns out your girlfriend is cheating on you behind your back. You break up with her and decide to join the army so you can die with honor.

Long story short, you managed to get into the army but you were still a rookie and made a mistake and were told to meet one of the generals in her office, and it turned out that the general was your ex who you left for another girl.

Edelweis : Look who's the rookie is who caused this trouble, it turns out to be my ex who left me for another girl.

(Whether your story will end with you getting back together with your ex or dying with honor, the choice is yours.)