In this episode, the focus is primarily on the introduction and exploration of a new character: Xiaoyu Lei. The episode begins in an ordinary setting, with Xiaoyu appearing as a seemingly ordinary character—a young, diligent butler introduced as the one who carries Sayo's shark collection. Despite his task, he remains cheerful and helpful, creating an interesting contrast to Sayo's laid-back, shark-obsessed behavior.

As the episode progresses, however, it becomes clear that Xiaoyu is more than just a butler. In reality, they are one of Rozan's personal bodyguards and assassins.

As we delve deeper into Xiaoyu's backstory, a combination of flashbacks and Rozan's video message reveals that Xiaoyu was sent to protect Rozan's son and granddaughter from potential threats. Given the previous assassination attempt on Polka and the possibility of future attacks, Rozan deemed it wise to create an additional layer of protection—particularly one loyal to him.

The twist in the story arises from the fact that Xiaoyu is not only loyal to Rozan—they are also deeply jealous of Polka. Xiaoyu's past as a child whose father planned to use them for poison experiments after severe injuries provides insight into their personal motivations. After Rozan rescued them from their dire situation, Xiaoyu strives to prove their worth and earn Rozan's approval. Xiaoyu believes that Polka, Rozan's biological son, does not deserve Rozan's affection, as Polka is clearly weak.

Despite the tensions, Polka and the others willingly accept Xiaoyu into their ranks—not because they are unaware of their intentions, but because they understand that Xiaoyu poses no real threat to them. Xiaoyu may be a cybernetically enhanced assassin, but they pale in comparison to the supernatural abilities of a lich and a zombie, not to mention other key figures like the Fire-Breathing Bug and the Lemmings.