Unaware of his advisor Watanabe's unethical methods to acquire the completed software from Ikumi's husband Momotarō, Isshin became an unwitting instigator of the conflict. Watanabe orchestrated Momotarō's arrest and pursued Kokone under the guise of corporate espionage, actions Isshin did not authorize.

Within the dream world of Heartland, Isshin parallels the King. This reflects his real-world authority and initial opposition to innovation. The King's control over the car factory and resistance to Ancien's (Ikumi's counterpart) use of the magic tablet mirror Isshin's initial rejection of disruptive technology.

After Kokone confronts him and reveals Watanabe's actions, Isshin acknowledges his past mistakes. He reconciles with Momotarō and Kokone, integrating them back into the family. Isshin supports the public demonstration of Ikumi's self-driving technology during the Olympics, culminating in a renewed familial bond and the fulfillment of Ikumi's original vision for the company.