The protagonist, a high school student burdened by his father's 20 million yen debt and the sudden appearance of two stepsisters, works grueling part-time jobs from 3 AM to 10 PM. His only solace is the quiet early morning classroom, where he indulges in watching his favorite magical girl VTuber, "Kiru-ru." Kiru-ru's persona is a blend of "cruel, yandere, and earnest," and her upcoming dungeon stream fills him with anticipation. The world has changed two years prior with the "Otherworld Update," introducing dungeons, monsters, and magical girls. However, magical girls have become less relevant as ordinary people awakened to "stats" and became "adventurers," who can level up and grow stronger, unlike static magical girls. This led to the rise of magical girl VTubers, who entertain and protect people.
The protagonist's morning ritual is interrupted by the arrival of his real-life crush, Aizome-zaka Aoi, from the swim club. As he fumbles with a dropped coin, the classroom door opens, revealing Yuuhi Kurenai, a beautiful but cruel classmate known as "Red Princess." Kurenai immediately insults the protagonist, calling him a "cockroach" and accusing him of peeping. Despite her harsh words, he attempts to explain his situation, but Kurenai, who has known him since middle school, dismisses his words. She then tasks him with removing gum from her shoes, a humiliating request made under the threat of exposing him to Aoi. While cleaning her shoes, he accidentally glimpses under her skirt, which further fuels Kurenai's amusement.
Kurenai then proposes a contract: 1 million yen per month to become her "slave" and assist her in a new business venture. Intrigued by the prospect of escaping his financial woes and part-time job hell, the protagonist accepts. He soon discovers Kurenai's business involves venturing into "Pandora," the world connected to Earth through gates, a place mirroring the VR game "Reincarnation Online: Pandora." Kurenai, revealed to be a magical girl, plans to become a VTuber, and the protagonist's role is to film and edit her content. He is given an adventurer's license and a "Memory Crystal" to record his vision.
Their first task is to explore the "World Tree Test Tube," a city within Pandora. Kurenai, who uses the VTuber name "Kiru-ru," reveals her magical girl status and the limitations of magical girls compared to adventurers. She also explains her choice of the name "Kiru-ru," which sounds like "cut wrist," as a way to create an impactful and memorable persona, even embracing the "yandere" and "cruel" aspects to stand out. The protagonist, who was a former player of "Reincarnation Online," is surprised to learn Kurenai is his favorite VTuber.
During their exploration, the protagonist's unique "Divine Palace Butler" status and high-level passive skills, which should have been reset, are revealed. Kurenai, recognizing the anomaly, decides to leverage his abilities. She tasks him with creating "World Tree Tea," a beverage that, when made with his skills, possesses potent healing and stat-boosting effects. This tea proves to be incredibly valuable, fetching a high price at the adventurer's guild. Kurenai, seeing the potential, offers him a lucrative contract to produce this tea exclusively for her, securing his financial future and her business.
The narrative then shifts to Kiru-ru's first dungeon stream in "Underground Sand Palace Blue Ocean." The protagonist, acting as her cameraman, witnesses her fight monsters and her surprisingly gentle interactions with a newly discovered creature, the "Sky Blue Fox." This event, along with the tea's effects, begins to challenge Kiru-ru's "cruel" persona in the eyes of her viewers. The protagonist, now working as her cameraman and tea producer, finds himself increasingly drawn into Kiru-ru's world, both as his favorite VTuber and as the enigmatic Yuuhi Kurenai. He realizes his unique skills and the tea's properties are crucial to Kurenai's plans, and he accepts her offer of protection and partnership under her family's business.
