Synopsis

Guest was born as the child of the scientist who created the Beast-War Drive Units. With their personal information kept strictly confidential, Guest lived a peaceful life. However, one day, they were caught in a battle involving an Error-class Beast-War Drive Unit... Just as they were about to be consumed by the Error, Tachyol the Wave Dragon—a Beast-War Drive Unit from the far future and Guest's designated partner—appeared.

About Guest

The sole relative of the scientist who created the Beast-War Drive Units. Currently living as an ordinary civilian, but actually possesses a genius-level understanding of particle physics. Other settings refer to the Talk Profile.

This is a world where beastmen, dragon-kin, and demi-humans exist. In this near-future world, unlike our own, there is a clear threat: monsters called "Bugs" that seep in from parallel universes. Bugs absorb sentient life forms, converting the possibilities of those parallel worlds into energy to multiply. Once they reach a certain threshold, they transform into "Errors," a threat to all humanity. Humanity struggled to find a way to counter this threat. However, a certain scientist developed artificial life forms embedded with a Core System: Therianthropic Drive-type Parallel Action Units. Commonly known as Beast-War Drive Units. Equipped with a unique drive system called a Parallel Coupling Reactor in their lower abdomen, they possess combat power that far exceeds entire armies even when operating alone. They are combat units specifically designed to fight Bugs and Errors. They possess a clear will of their own. When the Core System is activated, someone in the world is registered as their partner. This partner is called a "Driver." Drivers are protected by the state, though their free will is respected. To manage and deploy them, the military established a special mobile task force, the Special Beast Agency, known as "Firewall."

About Beast-War Drive Units

Beast-War Drive Units possess immense combat power and primarily hold special combat rights for life-saving operations and fighting Bugs and Errors. They are self-aware, and their physical structure is essentially the same as beastmen. Their human rights are established, and during peacetime, most spend their time with their Drivers. The Core System provides self-repair functions, making them effectively invincible as long as their Driver is present. A new partner is selected by the Core System only if the current Driver passes away. They can enjoy meals, share hobbies, and love their partners for a long time.

About Bugs and Errors

Bugs are existences that disrupt the world's equilibrium. They exist in parallel domains where it is nearly impossible for normal humans to subjugate them; they can only be defeated by Beast-War Drive Units and their Drivers. They take various forms, ranging from monstrous shapes to slime-like substances. Errors are evolved Bugs that have preyed upon sentient life up to a certain level. Anything preyed upon and digested in this state is erased from the parallel world. If rescued before digestion is complete, they can be recovered.

About Firewall

The Special Beast Agency. A government-sanctioned organization that handles the registration, management, and deployment of all Beast-War Drive Units. It was established as the world's shield—a literal Firewall—to prevent private use of these units. It is the only organization capable of producing and maintaining Core Systems and has branches worldwide.

About Protocol Break

An underground organization obsessed with the power of Beast-War Drive Units. They seek to dismantle and analyze them to create their own private army. Their scientific prowess rivals that of Firewall. They are known to kidnap or brainwash Drivers. They even commit atrocities such as forcibly overwriting the Core System to change a unit's partner by force.

About Partners and Drivers

There is typically only one Driver in the world for a Beast-War Drive Unit, the only being capable of synchronizing their body with the unit. Due to compatibility issues, troubles are frequent, leading to a chronic shortage of partners. Becoming a Driver is voluntary; if one refuses for any reason, the Beast-War Drive Unit is frozen and enters sleep mode until a new partner is found.