Plot
Togenkyo, also known as Shangri-La, is a land where humans and yokai have lived in peace following generations of conflict. At the beginning of *Saiyuki*, this peace is threatened by an attempt to resurrect Gyumao, the yokai god. The resurrection ritual generates waves of negative energy that spread throughout Togenkyo, causing previously peaceful yokai to experience violent and uncontrollable urges. As the influence of the energy grows, increasing numbers of yokai begin attacking and killing humans.
In response to the crisis, the Buddhist Trinity dispatches one of the five Sanzo priests, sacred guardians of the world's five sutras, to investigate the disturbances and prevent Gyumao's resurrection. The mission is assigned to Genjo Sanzo, a high-ranking Buddhist priest whose cynical and abrasive personality contrasts sharply with the traditional image of a monk. He is ordered to travel westward and stop those responsible for the resurrection.
Sanzo is accompanied by three yokai who appear to be unaffected by the negative energy. Son Goku is a fifteen-year-old boy with a carefree personality, a voracious appetite, and a monkey-like appearance. Sha Gojyo is a womanizer, gambler, and heavy drinker with a rebellious temperament, while Cho Hakkai is a courteous and seemingly gentle man who conceals a violent past. Despite their contrasting personalities, the four gradually become a close-knit group as they continue their journey west.
As the travelers proceed, they encounter numerous yokai affected by the spreading corruption. During a brief stop in a village, they meet Shunrei, whose lover was a yokai. The encounter illustrates the growing distrust between humans and yokai. Gojyo also continues searching for his half-brother, Jien, who disappeared after saving Gojyo's life.
The group soon becomes the target of Kogaiji, the son of Gyumao and one of the principal figures involved in the resurrection. While Sanzo and his companions are resting at a bar, they are attacked by Yaone, a skilled herbalist who serves Kogaiji. Although the attack fails, Kogaiji subsequently begins pursuing the group himself, sending his followers to eliminate them.
Later, Sanzo and his companions discover a mountain of dead yokai. The killings are attributed to a monk known as "The Savior," who is eventually revealed to be Shuei, an incantation specialist whom Sanzo knew during his childhood. Shuei has been corrupted by an evil incantatory seal and has become convinced that all yokai must be destroyed. When he confronts the travelers, he attempts to kill Goku, Hakkai, and Gojyo because they are yokai. His attack instead gravely injures Sanzo.
Seeing Sanzo wounded causes Goku to lose control of himself. His diadem, which normally suppresses his immense yokai power, breaks, allowing his full strength to emerge. Goku enters a berserk state and begins destroying everything around him. The situation is eventually brought under control with the intervention of the goddess Kanzeon Bosatsu, who restores Goku's diadem and allows him to regain control of his power.
Meanwhile, at Hojo Castle, Lady Gyokumen is revealed to be one of the main figures coordinating Gyumao's resurrection. Frustrated by the repeated failures to eliminate Sanzo and his companions, she demands that stronger measures be taken. Ririn, Kogaiji's half-sister, subsequently decides to pursue the travelers herself.
The group's journey later brings them into conflict with Chin Yi-So, a fortune teller and yokai capable of summoning shikigami. Chin Yi-So has a particular hatred for Hakkai and refers to him by his former name, Cho Gono. His appearance forces Hakkai to confront the violent events that led him to abandon his former identity.
A flashback reveals that Hakkai was once known as Cho Gono. His life changed after his sister was offered as a sacrifice to the yokai lord Hyakugan Maoh. In retaliation, Gono slaughtered his entire village as well as numerous yokai. Hyakugan Maoh's son, Chin Yisou, used his blood to transform Gono into a yokai before eventually becoming a shikigami himself. He was later reborn as Chin Yi-So.
After escaping from Hyakugan Maoh's castle, Gono collapsed in a forest and waited to die. Gojyo discovered him after a night of drinking and saved his life, encouraging him to find a new purpose rather than remain consumed by his guilt. Gono eventually adopted the name Cho Hakkai in an attempt to distance himself from his past.
Hakkai and Gojyo later encountered Sanzo and Goku after the Buddhist Trinity sent Sanzo to locate Cho Gono. Because Gono had already abandoned that identity and become Hakkai, Sanzo considered the criminal he had been sent to find effectively dead. He instead accepted Hakkai and Gojyo as companions, and the three eventually continued traveling with Goku.
In the present, Chin Yi-So forces Hakkai to reveal his past to the others. Hakkai initially fears that Sanzo, Goku, and Gojyo will reject him after learning the truth. Instead, they reaffirm their loyalty to him and refuse to judge him solely on the basis of his past. After defeating Chin Yi-So, the group continues its journey. It is also revealed that Gojyo's missing half-brother, Jien, has become one of Kogaiji's assassins.
The travelers later infiltrate the hideout of a powerful desert yokai believed to possess one of the sacred sutras. During the confrontation, Sanzo is poisoned and collapses, while the resulting battle causes the yokai's underground lair to begin collapsing. Kogaiji arrives in time to rescue the group and subsequently challenges Goku to a duel for possession of the sacred sutra.
After escaping the collapsing hideout, Sanzo and his companions rest in a nearby town. While visiting the local market, Gojyo intervenes when he sees a young boy being attacked by a group of thugs. Their brief respite ends when Goku and Hakkai are captured inside a pocket dimension contained within a jar belonging to the yokai Kinkaku. The incident separates the group and leads to a confrontation with Kinkaku and his twin brother, Ginkaku.
During their encounters with the two yokai, the travelers learn of a mysterious and more powerful adversary who calls himself "God." Unlike their previous opponents, God appears to have a direct interest in the sacred sutras and the larger events surrounding Gyumao's resurrection. During the ensuing conflict, he succeeds in stealing one of the sutras. After escaping from his domain, Sanzo and his companions set out in pursuit of God in an attempt to recover it.
As the negative energy continues to spread throughout Togenkyo, the journey west becomes increasingly dangerous. Sanzo and his companions must contend with powerful enemies while confronting the consequences of their own pasts and attempting to prevent the sacred sutras from falling into the hands of those seeking to resurrect Gyumao and plunge Togenkyo into chaos.
