Stratosphera no Yousei - Season 1

A young programmer, working late, observes an unfamiliar beautiful girl on his balcony. She is watching a couple in a nearby building. After she leaves, a distinct fruit fragrance remains. He feels compelled to find her, unaware she is extraterrestrial. This occurs in a near-future world damaged by human neglect. Five angelic nymphs have descended from the stratosphere. They carry the scent of forbidden fruit and seem intent on providing pleasure to the devastated human race.