Baron Kaidō leads Root Academy as headmaster, scouting globally for talented young puzzlers and bestowing distinctive titles in recognition of their abilities. His full name, written as 解道バロン (Kaido Baron), signifies his key role within the institution.

Concealed beneath this role, he operates as section-chief of Section Φ within the organization POG, enjoying considerable autonomy. He fundamentally opposes POG's shift towards deploying lethal puzzles designed to eliminate solvers and covertly resists this directive. To counter POG's dangerous path, he recruits Souji Jikugawa into his section, leveraging Souji's skills to guide protagonist Kaito Daimon and his companions towards the Puzzle of God as part of his strategic resistance.

His connection to Kaito Daimon extends beyond academia; he brought Kaito to Root Academy, and flashbacks hint at deeper, undisclosed involvement in Kaito's past. This mentorship positions him as an indirect ally to Kaito's group against POG's extreme factions.

His dissent leads to severe consequences: POG arrests him for insubordination and defying orders, removing him from his position. While his direct presence diminishes after this, his foundational influence endures through the characters he mentored and the ongoing conflict against POG's lethal puzzles.

His motivations consistently focus on protecting young puzzlers from exploitation and ensuring puzzles remain challenging yet non-lethal tests of intellect.