Yamajii, a middle-aged Akamatsu Industries employee, serves on the Neuronoid pilots’ support team alongside Li-chan, sharing a camaraderie-filled dynamic marked by playful banter. Engaged in covert missions against Algernon-linked threats, he repeatedly survives clashes with hostile entities that claim others’ lives. His resilience and practicality ensure his recurring presence during crises, though he counters stress with humor and occasional alcohol. Post-trauma beer-drinking rituals with Li-chan exemplify his habit of leveraging levity as a survival tactic. His tendency to deflect darkness with humor positions him as a grounding anchor amid the narrative’s escalating horrors. Though removed from Neuronoid piloting duties, he focuses on technical and logistical tasks critical to operations. Collaborations with colleagues, particularly Li-chan, highlight their reliance on teamwork and mutual trust. His background remains largely unexamined beyond his professional contributions, yet his consistent survival and presence across crises cement his role as a secondary but enduring fixture within the narrative.