The Oedipal pattern begins the moment the player starts a new game in the dream that plays before the Prologue. The Prologue also links the Reflector itself, in other words the ADMS system so central and distinctive to YU-NO, to the Oedipal pattern. In his letter to Takuya, Koudai writes of the Reflector: “The mirror is Keiko’s memento. Consequently, this strong connection to your real mother will become the trigger to tightly bind you to that place.” The place Koudai refers to is Triangle Mountain, where he meets and makes out with Yu-no and where a machine warps Takuya to meet the woman, identical to Kaytia, whom he will impregnate with Yu-no, who is also identical to Kaytia. A naïve reading might maintain that the “strong connection” to the mother suggests the centrality of (healthy) familial love to YU-NO, that Kaytia’s love for her son, in the same manner as the “flow of causality,” transcends “time.” In this reading, the unquestioning affection and protection she and her chest afford Takuya in his dream, this mother whom he longs for as she died when he was so young, demonstrates the power of family. But given the surrounding narrative, the incestuous subtext of the dream, and that Takuya’s future wife is a woman so identical to Kaytia that Takuya initially mistakes her for his mother, Koudai’s message assumes a dark meaning: at Triangle Rock, your obsession with banging your mom will guide you to do your daughter who looks like Kaytia doggy-style. In YU-NO, however, this meaning is not dark but positive. In the Prologue itself, Takuya must be content to “merely” make out with his daughter.
The most obvious manifestation of the Oedipal pattern is that Takuya lusts after his stepmother, Ayumi. While not blood-related, both Ayumi and Takuya are steadfast in referring to each other as mother and son. In the Prologue, Ayumi’s longest scene features her preparing and eating a late dinner with Takuya. In YU-NO, cooking meals is always a maternal activity and, not coincidentally, associated with women the player is meant to find sexually attractive. Only Kaytia analogues, namely Ayumi, Kanna, and Sayless, cook for Takuya.
Almost every time Ayumi is on screen, particularly early on, Takuya expresses strong sexual attraction to her. The player is shown her panties and breasts and invited to click around her anatomy to the same degree as every other possible sexual partner, suggestive of how Takuya always sexualizes his stepmother, even if he often chides the player for encouraging his lust over his “mother’s” breasts. Takuya repeats variations of “She’s my mother, damn it. What am I thinking?” ad nauseam: “Ayumi-san is in her lingerie… It’s not indecent, but rather it’s refined, and faintly seductive. […] It’s my mother, damn it. What am I getting so worked up about?” In multiple flashbacks, Koudai mocks Takuya over his son’s jealousy of Ayumi: “Could it be that… you’re jealous? […] I’m impressed, my son. […] Whahahah! Have you ever considered confessing, huh?” In another flashback-dream in Kanna’s apartment, Koudai ridicules Takuya as “Mr. Mother Complex.”
In a dream in Ryuuzouji’s storehouse, Koudai mocks Takuya again for his attraction to Ayumi:
In the Mitsuki route, Mitsuki also teases Takuya for moaning Ayumi’s name during sex:
