Roundabout (OTSU Hiyori)

Oono Chiharu and Kawahara Asami used to be a couple during their high-school years. When Chiharu suddenly moves away without a word, Asami is left with nothing but a broken heart and memories of first love that aren't quite so easily forgotten.

Seven years later the two meet again as career women; Asami recognizes Chiharu immediately, but the latter gives no indication that they've ever even met before. Furious and feeling as though she were betrayed all over again, Asami vows to give Chiharu a taste of her own medicine...