Not really, but it could be interpreted as such. To note, a character who is in love with a child character's age is kind of ambiguous due to the art style. Similarly, a child character falls in love with an adult woman and is kissed by her towards the end but she doesn't exactly reciprocate (romantically). The aforementioned scene makes a lot more sense when you have the context.
They aren't blood related but a child character is kissed by their motherly figure near the end of the movie, it might be an uncomfortable scene for some.
There is a scene where an adult character undresses in front of a child character, however said adult has no sexual intent and uses her clothes to cover a robot's dead body. Her body also features many robotic features under her dress.
Many characters in the movie get mechanised bodies because they are unsatisfied with their own, or they are unsatisfied with their mechanised bodies and wish to return to their old ones. This can be seen with various characters through out the movie.