Otonarisan wa Alien

Jin Takao just moved into his new apartment and is adjusting to life in a small town. On his way home one day, he encounters a woman moving into the same apartment complex. He notices that she's having some trouble getting a box up the stairs and offers to help, but when he gets closer she loses her balance and falls back on him. Distraught that she hurt Jin, she invites him to her place for some "first aid"... (Source: BakaBT)