"Made in Abyss: The Golden City of the Scorching Sun" is the second season of the "Made in Abyss" series, continuing the story of Riko, Reg, and their perilous journey into the depths of the Abyss. The season adapts the "Idofront" arc from the manga, focusing on their arrival at the Sixth Layer, known as the Capital of the Unreturned. This layer is home to the Golden City, a mysterious and ancient settlement filled with remnants of a lost civilization and inhabited by strange creatures and beings.

The narrative centers on Riko and Reg as they encounter a group of Hollows, humans transformed by the Abyss's curse, led by a figure named Vueko. Through flashbacks, the story delves into the history of the Golden City and its connection to an expedition led by a man named Wazukyan. This expedition, known as the Ganja Corps, ventured into the Abyss decades earlier, seeking the Golden City and its secrets. The flashbacks reveal the tragic and harrowing events that led to the creation of the Hollows and the city's current state.

As Riko and Reg explore the city, they meet Faputa, a unique and powerful being who claims to be the "Princess of the Hollows." Faputa's existence is tied to the city's history and the experiments conducted by the Ganja Corps. Her motivations and connection to the Hollows become a central focus, as she seeks to fulfill a mysterious purpose tied to the city's destruction. The season explores themes of survival, sacrifice, and the consequences of human ambition, as the characters confront the moral and physical challenges posed by the Abyss.

The main characters, Riko and Reg, continue to develop as they face new dangers and uncover the Abyss's secrets. Riko's determination to reach the bottom of the Abyss and find her mother drives her forward, while Reg's loyalty and protective instincts are tested as they encounter increasingly hostile environments and adversaries. The season also introduces new characters, such as Vueko, Wazukyan, and Faputa, whose backstories and motivations add depth to the narrative and expand the lore of the Abyss.

The plot intertwines the present-day journey of Riko and Reg with the historical events of the Ganja Corps, creating a layered and immersive story. The Golden City serves as a backdrop for exploring the Abyss's mysteries, its inhabitants, and the ethical dilemmas faced by those who seek to conquer it. The season builds on the established world-building of the series, introducing new elements that deepen the understanding of the Abyss's nature and its impact on those who enter it.