It's not okay to break up siblings.
Gilbert works at his country's border and is responsible for sending immigrant orphans to different orphanages.
Gilbert wants to serve his country.
Gilbert knows that humanity sometimes supersedes the written rules, and makes sure to keep two orphan immigrant brothers he encounters during his work together with one another.
Gilbert follows the letter of the law of his country and finds himself in a situation where he sends two brother orphan immigrants to separate orphanages.
The two brothers that Gilbert kept together are very happy to have one another.
The brothers that Gilbert separates become frightened and grow up to resent the separation that was forced on them.