Soul mate is some one (the opposite sex) who can understand you, reliable ( maybe a good person in your view ). Some one you can be yourself when talking or doing everything together. You always feel happy, pleasant when you are with him/ her.
That's what I thought by watching film.
I don't know if soulmates, but I love the idea of it.
Here's my take on it. I think a human being has several layers- physical, soul and spiritual.
The physical being is what you can see, touch, smell, have fun with, talk to as an intellectual equal (I say this because you can do the others with a pet or non living things as well :P)
The soul is what makes a person unique, it is an abstraction of the being. Personality, taste, energy dynamics, feelings come into picture.
I think, a soulmate could be someone you connect with on a Soul level. So, they make you "FEEL" connected to them in some MEANINGFUL way, as though they have an important role to play in the story of your life.
I also think we could possibly have five-ten soulmates in a life time. It could be exes, soul sisters or someone who changed your path in life in someway.
Based on the context of your question, I get what you're asking, and I have some interesting material you would want to read :)
I wish you good luck [emoji][emoji]
https://soulflowerinbloom.blogspot.in/search/label/LOVE