I hope that the manga will not push a romantic relationship between her and the shop owner because the inner thoughts of both that they showed here threw up all sorts of red flags should things go that way. On one hand Nao is really emotionally insecure and, presumably due to past trauma, seems to have huge issues judging people and relationships. For Takeru he seemed to spend half the chapter dwelling on how she reminded him of his past girlfriend, who he misses dearly, which is not a healthy way to start a relationship with a new person either.
That is not even going into the sketchy age difference...