Isshin Shijima presides as chairman of Shijima Motors and monarch of Heartland’s fantasy realm. In reality, he is father to Ikumi, whose tragic death during a self-driving car test—a project he once dismissed as impractical—left him haunted by regret. His initial rejection fractured their relationship, driving Ikumi to flee with mechanic Momotarō to pursue her vision secretly. Determined to atone, Isshin revived her abandoned work, unveiling its success at the 2020 Tokyo Olympics to honor her memory and confront his past resistance.

As Heartland’s King, he governs a mechanized society besieged by a molten Colossus and political betrayal orchestrated by his advisor Bewan, a counterpart to real-world rival Watanabe. Mirroring his skepticism toward Ikumi’s innovations, the King initially opposes Ancien’s use of a magical tablet to animate machines, clinging to tradition. Yet he gradually acknowledges Ancien’s ingenuity, embracing her methods to safeguard his kingdom—a parallel to his real-world evolution toward accepting progress.

His journey intertwines generational divides and the peril of inflexibility. Flashbacks reveal his younger self clashing with Ikumi and Momotarō, his disapproval of their partnership starkly contrasting his later efforts to connect with granddaughter Kokone. By the story’s end, he strives to reconcile heritage with innovation, symbolizing a transformation from staunch traditionalist to a leader valuing both legacy and advancement.

Spin-off media, including *Ancien and the Magic Tablet: Another Princess*, expands his portrayal as a remorseful figure driven to mend past failures, his actions in dual worlds united by a resolve to protect his family’s enduring influence.