Talk about a throwback. I had two friends when I was in elementary school give me these necklaces and as soon as they did, I fell in love with having those silly half hearts with me at all times. Then I had a bestie in 5th grade and gave one to her and a year later we both decided we were too cool to wear them but both kept them in respective sentimental boxes.
But, as with so many throw-back, hipster-esque styles, I think it would totally rock to wear a bright red half bestie heart with your Tuesday-at-the-office-ruffle-top-and-blazer. Give the other half to the apple of your friendship eye and hope she feels similarly.