In corruption studies, megaprojects which involve substantial public funds are often considered “elephants in the room”, requiring close monitoring. This chapter employs a case study of a significant grand political corruption case in prewar Japan to examine Taishinin’s attitudinal, goal-oriented and strict judicial behaviour. The relocation of the fish market from Nihonbashi to Tsujiki following the Great Kantō earthquake was a megaproject involving significant financial compensation. Two primary stakeholders exercised proprietary rights and engaged in systematic bribery of Tokyo City Assembly members through leaders of political factions. The objective of this strategy was to maximize the compensation amount to be received from the Tokyo government. The intricate network of corrupt transactions and compensation agreements persisted for a period spanning multiple years. In the context of cultural defence of character, a controversial legal strategy, an appellant advanced the argument that certain transactions were driven by cultural motivations.