I also appreciate just how long it goes on after the final battle against the antagonists; almost half the manga takes place after that point. There's enough time for the characters to properly bounce back from that and to get to back to the real point: the parallel stories of adults and children dealing with stress.
The adults face hectic work and tough decisions, while the kids face the veil coming down from their eyes and the world showing its ugliness for the first time. Both of them seek comfort by returning home, but they've spent so much time fragmented that it's hard for them to work out a balanced family dynamic.
To vainly use some social psychology jargon: there are two kinds of support that can help alleviate the autonomic response that comes with stress: tangible and emotional support. The characters begin to surround themselves with people who can offer them both, while working out issues of interpersonal trust.
The fantasy allows for direct, creative metaphorical imagery which keeps it fresh while continuing to acknowledge the various problems faced by the characters; the probable best example of this occurs fairly late in the manga, and asks us to recall everything that Ran's been through up to that point while she struggles to cope with a brand new experience.
It's a pretty unabashedly sentimental thing that unquestioningly accepts its own ridiculous reality. But it doesn't cut corners to reach that sentiment, and for that it's very uplifting.
