The money scandal that led to the resignation of Akira Amari as economy minister makes yet another case for an overhaul of the system regulating political donations, which has a history of being amended in response to recurring money problems involving senior lawmakers and businesses but left with loopholes.

Amari, a close political ally of Prime Minister Shinzo Abe, quit his Cabinet position last week after admitting that he and his secretaries received millions of yen in cash and benefits in 2013 and 2014 from a construction firm that allegedly asked his office to intervene in talks it was having with a government-funded housing corporation for compensation related to a road construction project in Chiba Prefecture. While acknowledging receipt of the money, part of which was "privately" used by one of his aides, Amari denied his office used its influence to turn the negotiations in the company's favor, and the Urban Renaissance Agency (UR) — whose officials met with Amari's aides a dozen times — says its decision to award the company more than ¥200 million in damages was not the result of meddling by the veteran lawmaker's office.

It has yet to be established whether any law has been broken, including the anti-graft law, which prohibits lawmakers and their aides from receiving financial benefits for using their power to influence contracts and administrative decisions involving national and local governments. The UR released what it says are partial records of the conversation between its officials and Amari's secretaries, which do not show that the aides made outright demands or put pressure on the officials to influence the talks with the construction firm. It's not clear whether mere contact from the office of a powerful ruling party lawmaker asking for "explanations" on a dispute involving government institutions in itself served as sufficient pressure. What seems clear is that business donations to individual politicians — which was supposed to have been banned in the amendments to the Political Funds Control Law in the 1990s — effectively remain business as usual today.