This harsh adherence to authority is why Takuya thinks to refuse sex with his daughter for no rational or ethical reasons but on the basis of Japanese law: in YU-NO, the rules laid down by authority are morality. Takuya cannot achieve deliberate, true incest in Sakaimachi not for reasons of principle or personality but because doing so would defy legal authority, as only “bad” characters like Kaori can do. But in Dela Grante the ultimate taboo can be violated because Japan’s laws do not apply to Dela Grante—because, in other words, this act does not violate the will of the God Emperor, who in the Prologue tells Takuya she wants him “to walk wholeheartedly on the path [he chooses],” evidently including having sex with his daughter. And how fitting that Kaytia and Yu-no are both loyal priestesses who sacrifice themselves for the God Emperor with no regrets, analogous to their obsessive devotion to Takuya. In comparison, Sayless, the only of Takuya’s mommies who defies the pillar of Koudai-like violent and destructive patriarchal authority that is the God Emperor, suffers assault and a miserable death.
In the Epilogue, the Oedipal pattern becomes infused with literal pedophilia and then with a psychological pedophilia based on the player altering their adult daughter’s brain to “free” her from adulthood, to regress her to childhood while ensuring she remains under the established authority, i.e. the God Emperor. The introduction of Yu-no highlights the desire for firm masculine control over the sexual partner. Where Takuya’s previous simulated incest (Ayumi) and true but unknown incest (Kanna) involve sex between mature individuals, Yu-no remains a child to the end. Furthermore, like Takuya abandons the possibility of growing up because this is the player’s presumed fantasy, Takuya also must actively remove adult maturity from his daughter so that she can remain more pet-like than Sayless. For an eroge milieu that commonly pandered to pedophilia, this may be highly romantic.
For Koudai, and so for YU-NO, love is conditional on servitude and the fulfillment of certain social roles. Only those who fill their roles deserve it. Even Koudai’s apparent kindness and support for Kanna is quid pro quo, though the story depicts Kanna as pleased to fill her role. In exchange for Koudai’s paternal love, Kanna becomes his loyal servant there to ensure Takuya proceeds down the road the old man laid out for him. She is so loyal, in fact, that in at least one bad ending of the Mio route, she apparently sacrifices her life merely to remind Takuya to use his Reflector, allowing herself to be sealed in the cave beneath Sword Cape.
If Koudai’s son shows emotional vulnerability, even as an infant, then his son is insufficiently masculine and deserves no compassion. Hence Takuya never learns to show people more respect and never outgrows his incestuous obsessions. Koudai has one mission for Takuya: impregnate Sayless so that her daughter can fulfill the rite that saves (at least) two universes. Hence Takuya does achieve this goal. Once Takuya has completed his role as Koudai’s tool, fulfilling his mechanistic destiny as a penis in the causal chain, he has reached the end of the path he wholeheartedly chose, the path his father chose for him, and YU-NO ends with Koudai’s approval. Takuya’s yearning for and attainment of a pet-like partner, in other words, and in smaller scale, his desire to be a controlling god himself and his hierarchical obedience to his father’s will to sire Yu-no win Koudai’s respect. Takuya as a person is incidental. In these dehumanizing gender roles, Takuya is valued for embracing Koudai’s idea of masculinity and for the function of his penis. Takuya is valued, in other words, only as an object that fulfills the fate the dictatorial father lays out for him.
While a small point given that such matters are broached only in throwaway moments, the script also insults characters who step outside of Koudai’s brutal, rigid, violent gender ideals. For instance, “Woman B” participates in the protest against Geo Technics. Woman B is a trans woman whom the player can choose to sexually assault by licking her as slapstick comic relief before Takuya berates and misgenders her:
Kanno vindicates the gender ideals of Koudai’s way of living in the extreme masculine aggression and insecurity of every man except Yuuki and in the extreme feminine submissiveness in the chief women, Ayumi, Sayless, and Yu-no. To disobey these roles like Woman B warrants Takuya’s revulsion. The true ending sidelines the more proactive and independent women in favor of rewarding the player with sex with their shallow and dependent daughter. The least passive and feminine women, Eriko and Kaori, are denied their own story routes. Those like Woman B who step outside of Koudai’s way of living are demonized or insulted, save the rebel Amanda, who, with Takuya, is instead easily persuaded become a collaborator. Rebellion is unserious. Amanda’s rebellion barely qualifies as such, in any case: she is never seen engaging in any kind of organization or combat. Her fight is an abstraction. Even Eriko, a woman in the main cast with considerable agency and also a rare character with motives unrelated to Koudai, is degraded in all but one of her erotic scenes, always acted upon without her consent. Eriko’s sexual humiliation, as when Takuya spies on her changing, makes out with her while she sleeps, or plays with her privates when she is stuck on the wall of Ryuuzouji’s estate, is always a joke precisely because it undermines her agency. At one point she acknowledges her distress, chastising Takuya for violating her: “to think you would overstep ethical boundaries like that…” She then leaves to be alone a while.
The fantasy of the Yu-no character is patriarchal to the point of dysfunction: one of a female pet for a sexual partner. It is ironic that Takuya never has sex with his actual pet, Kun-kun, another nude, buxom anime girl whom he eats instead.