According to Wikipedia:

Gekiga (劇画), literally "dramatic pictures", is a style of Japanese comics aimed at adult audiences and marked by a more cinematic art style and more mature themes. Gekiga was the predominant style of adult comics in Japan in the 1960s and 1970s. It is aesthetically defined by sharp angles, dark hatching, and gritty lines, and thematically by realism, social engagement, maturity, and masculinity.

Yoshihiro Tatsumi is often credited as the creator of the Gekiga movement, a strong art if compared to what was dominant at the time (kids' shows that became a foundation for the later movement Shonen).

Abandon the old in Tokyo published by Drawn and Quarterly (April 10, 2012) is a collection of 8 tales written between the late ‘60s and early ‘70s and represents a good starting point to approach the narrative of Tatsumi. Most of the tales are included into this Daihakken.
James Defebaugh states, “Though a quick read, Abandon the Old Tokyo is certainly not a light one. Its stories provide an unflinchingly honest expose on the private lives of ordinary, working-class men living in the hustle and bustle of Japan’s thriving metropolis that will more often than not leave the reader disquieted, contemplative, morally troubled and a little haunted.”

Tatsumi empathizes with the working class, work is seen as humiliating for both body and soul, and the machines are horrible monsters who overwhelm our own voice reducing the human to a silent tool who feeds the machine (Beloved monkey page 86). The characters themselves are depauperized of their humanity and become mere animals (Unpaid page 130), all this for the sake of money and business (Unpaid page 121).

The working class suffers from alienation and is forced to wander around like a bug nest, where no one cares about the other, letting the characters suffocate (Beloved monkey pages 87-88). This solitude is evident in the lack of empathy of those around us, while a man is carrying in total indifference the corpse of his dead mother (Abandon the old in Tokyo page 67).

In this abomination sex becomes barbaric, the characters do not enjoy it, they do it out of desperation or out of poor nihilism similar to wild animals. As Win Wiacek pointed “Sexual frustration, human obsolescence, dislocation, impotence, isolation and futile acts of misplaced pride are depicted in rat-run mazes populated by a succession of hookers, weak men, disaffected women, ineffectual lovers and grasping dependents through recurring motifs of illness, retirement, injury and inadequacy in ramshackle dwellings, grimy streets, tawdry bars and sewers obstructed by things of no further value: pots, pans, people…”

There is no escape or solution it is like a spiral with no beginning or end as those of Uzumaki, even the artist is intoxicated by it, the mangaka should “Influence the children and not the other way around” (Occupied page 14), a prominent critic to a loss of integrity mangakas were having in favour of the commercial appeal.

Art itself is drawn into a hole full of slimy water (The hole page 153)