Isolationism in Underground Men?

Revisiting my first comparative paper on Superman, Champion of the Oppressed! and The Mysterious Underground Men, I’m intrigued by something I didn’t notice in Tezuka’s work the first time around. In it, Mimio is first presented to a group of scientists as “a most strange rabbit,” that –without the proper probing and electro-shock therapy—is by all accounts a violent creature (10). After its initial presentation, Mimio beats and humiliates a noted scholar; following his/her transformative surgery, however, Mimio is regarded by all as “practically human,” but doesn’t get any respect until he/she’s dying. Why is it that Mimio is treated by biological humans just as negatively as the Termites, despite the fact that he/she is on the human’s side? I wonder if we could connect this narrative element to some form of isolationist sentiment the Japanese may have felt after their surrender in 1945. This is just speculation, but, considering that Tezuka grew up in an American-Occupied Japan (much like Yoshiro Tatsumi)-, is it possible that his work on Underground Men references sentiments the Japanese could’ve felt towards outsiders immediately following the Second World War? Or could it have been a reference to the time before Japan's first encounter with the West only 100 years or so before the making of this comic? These aren't rhetorical questions, I'm just genuinely wondering if anyone thinks there could be a cultural/historical reason outside of the "what does 'being human' mean?" theory for why Tezuka depicted the unjust ostracization of Mimeo.