Perhaps the most well-known form of fanservicing in the manga is when readers see Chito and Yuuri Expies in Chapter 13 of the manga. It was once established that Tsukumizu possibly reused both of them for the manga's The Cameo, as Shimeji Simulation was done through pre-existing characters that were made by him, prior to the manga's release.
The Antagonist Theory?
In Chapter 30, The Climax of the manga, while it was assumed that either The Gardener or Shijima's sister was inclining into the Big Bad territory, it is soon revealed that this is a classical example of the Idealist vs. Pragmatist trope, resulting in a Good vs. Good event:
The Gardener is an idealist, who is the sole creator of West Yomogi, and has established rules to her own will. This is due to the fact that zero deaths have been reported, a byproduct of her attempts to create a utopia society.
Shijima's sister, on the other hand, is a hardline pragmatist, whose smarts are compounded by her inventions, including the Raw Fish Converter and the Raw Fish Generator, both of which used to create Fish With Names, the major power source used to send anyone into the dream world. Given The Reveal that West Yomogi was a mere simulation, it does not come as a surprise that she almost inclines into Pragmatic Villainy, but more so to dismantle West Yomogi's foundation and radically alter it.
