The group, known as Suigetsukai, was discovered to have omitted the income from political fund-raising parties held in 2020, with the undisclosed sum specifically coming from the Chiba prefectural building contractors political union. While admitting to this mistake, Ishiba categorized it as a simple administrative oversight and affirmed his commitment to rectifying the reporting imbalance. Despite previous assertions on a television program regarding the accurate listing of his faction's financial activities, it was revealed that there were indeed discrepancies in the income and expenditure reports.
Moreover, the scenario echoes a similar scandal that led to the resignation of Fumio Kishida, Ishiba’s predecessor as the Prime Minister, due to mishandling financial improprieties within the party's factions earlier in the year. The revelation prompted Ishiba to acknowledge the error during a parliamentary session on October 9, apologizing for the oversight while denying any illicit use of the unreported income as a slush fund. In compliance with the Political Funds Control Law, the faction is mandated to disclose the names and monetary amounts of individuals and organizations purchasing party tickets exceeding 200,000 yen per party in their financial reports.