It is eventually revealed that Souichirou died of stomach cancer; instead of receiving treatment, Souichirou had invested his remaining time into solving the virus code Kurosaki had been forced to reproduce in order save Kurosaki.
Schließlich wurde bekannt, dass Sōichirō an Magenkrebs starb; statt sich behandeln zu lassen, investierte Sōichirō seine verbleibende Zeit darin, Kurosaki zu retten, indem er den Viruscode unschädlich macht, den Kurosaki gezwungen war, zu verbreiten.