Midori Matsushima
Japan's Justice Minister Midori Matsushima arrives at Prime Minister Shinzo Abe's official residence in Tokyo, in this Sept. 3, 2014 file picture. Reuters/Yuya Shino

Update: Justice Minister Midori Matsushima has resigned following allegations of violating Japan's electoral laws, Reuters reported Monday, adding that Matsushima's resignation, along with the exit of trade minister Yuko Obuchi only a few hours earlier, deals the biggest blow of Prime Minister Shinzo Abe since he came to power in 2012.

"I appointed them and as prime minister, I bear responsibility," Abe told reporters at his office, Reuters reported. "I deeply apologize to the people of the nation," he said, adding that he would like to pick successors within the day.

Japan’s trade minister, Yuko Obuchi, who was considered a future contender for the post of prime minister, resigned Monday amid allegations that she misused campaign funds. However, Obuchi did not admit to any wrongdoing.

A local news magazine had alleged that Obuchi’s constituency had spent about 26 million yen ($245,600) on theater tickets for her backers in 2010 and 2011, according to Reuters. Once other newspapers in the country began reporting on the claim, yet another allegation surfaced claiming that her political funding oversight body had spent nearly 3.6 million yen over five years since 2008 on a design office run by her sister and a clothing shop run by Obuchi’s brother-in-law.

"I take seriously the impact I have caused," Obuchi said at the news conference, according to The Associated Press, or AP, adding: “My heart is pained by this."

Obuchi reportedly said at the news conference that the investigation would interfere with her duties, which include supervising the cleanup and decommissioning of the Fukushima Dai-ichi nuclear power plant.

Obuchi, the daughter of former Prime Minister Keizo Obuchi, was one of five women appointed by Prime Minister Shinzo Abe to cabinet-level posts in last month’s reshuffle. The resignation could hit Abe’s efforts to promote women to leadership roles in Japan's traditionally male-dominated society.

Abe's previous cabinet -- when he was the country's prime minister briefly in 2006 and 2007 -- had witnessed several scandals, forcing many of his cabinet members to resign, according to Reuters. However, the current Abe cabinet has been relatively scandal-free.

"I apologize for not being able to make any contributions as a member of the Abe Cabinet in achieving key policy goals, including the economic recovery and a society where women shine," Obuchi said, according to AP, adding that an inquiry initiated by her had not found any proof that funds were being used for personal reasons.

"This is my own fault and I will focus on investigating so that I can retain trust from my supporters as soon as possible," Obuchi said, according to AP.