The Long Cavern

The Long Cavern summary:

Moriyama is a well-off executive director of a high-class company, with a wife and two children. However, Moriyama isn't all he seems: He is in fact a Zainichi Korean who changed his name and identity after the war to shield himself from discrimination. One night, he is asked by an old friend to shelter a fellow countryman, Jo, who has come for his own reasons. Moriyama, who has distanced himself from his roots until now, must confront not only his heritage, but his past.
A sealed one-shot of Tezuka's focusing on Zainichi Koreans, it has never been recollected or reprinted in any capacity.