I just still can’t understand the meaning of the title

"Beware of Ides of march" is the actual title of the story, they just translated it I guess. Considering 'ides' means the fifteenth day of all the months with 31 days, which full moons occur, I say it's accurate.
As for the phrase itself, its from the Shakespearean play, 'Julius Caesar' where some witch or something (I don't really remember) tells Caesar to be careful at the full moon in March.(And he really did get stabbed that day lol)

As for how tgat relates to the story.... your guess is as good as mine.