In the wake of Shinzo Abe’s assassination last month, which the suspect claims was motivated by the former prime minister’s connection to the Unification Church, the relationship between Japanese politics and religion has come under increasing scrutiny — with experts suggesting that it is both widespread and pervasive.

On July 21, opposition parties led by the Japanese Communist Party began a probe into ties between the Unification Church and the nation’s lawmakers, including those from the ruling Liberal Democratic Party.

Examples have already begun to emerge: Nobuo Kishi, the defense minister and Abe’s younger brother, said last week that he had received help from Unification Church volunteers during elections, joining a list of other high-profile names within the LDP to admit to varying degrees of involvement with the organization.

Underpinning the controversy is the conduct of the church, particularly the way it is seen to have solicited money from followers — often by instilling the belief that a past debt has to be repaid in order to save the souls of their suffering ancestors.

The group’s activities drew accusations of brainwashing in the 1970s and '80s, and the arrest of a number of church leaders in the mid-2000s invited renewed scrutiny of the group, but without a widespread clampdown on the exploitation of its adherents.

The mother of suspect Tetsuya Yamagami, 41, is reported to have donated around ¥100 million to the Unification Church — a new religious movement founded in the 1950s in South Korea — ruining the family’s finances and ultimately leading to her son’s animosity toward Abe.

At a news conference Friday, the National Network of Lawyers Against Spiritual Sales, a group of lawyers representing victims of the church, told reporters that Abe had on more than one occasion sent congratulatory messages to a Unification Church affiliate group, including a video message for a gathering held in September last year — which Yamagami is said to have viewed online.

For North Carolina State University’s Levi McLaughlin, an expert on the relationship between politics and religion in Japan, the fact that connections exist between lawmakers and the Unification Church should come as no surprise, given the prevalence of religious and other interest groups active in the nation’s politics.

For the lawmakers identified, he said, the Unification Church was likely “one of many, many other groups that they were involved with.”

Some of these groups — such as Shinto Seiji Renmei (the Shinto Association of Spiritual Leadership) — are openly religious, while others — such as right-wing lobbying group Nippon Kaigi (Japan Conference) — are “incorporated differently.”

In all cases, McLaughlin added, there is a benefit to be had politically, as such groups provide an enthusiastic, committed pool of volunteers and other workers within an organizational structure capable of either generating votes or supporting lobbying on key issues.

As was revealed in Kishi's case, the Unification Church has provided unpaid volunteer support to some LDP lawmakers while on the campaign trail. The defense minister spoke Tuesday of the need to "review" the support he had received from the group in the past.

"There are many different issues arising from this case and it is clear that it is becoming a social problem," he said. "It is therefore only natural that we review the relationship."

Given the group’s coercive recruitment methods — such as convincing believers of the need to atone for the sins of their ancestors during Japan's colonial rule of the Korean Peninsula from 1910 to 1945 — participants may have felt compelled for religious or spiritual reasons to lend their unpaid support to certain politicians.

Other religious groups employing far less controversial recruitment and fundraising methods are also active in mobilizing electoral support and securing votes.

The LDP’s junior coalition partner Komeito, for instance, generates much of its support through its connection to the Soka Gakkai Buddhist movement, which for decades has been Japan’s biggest and most influential organized voting bloc and a major source of votes for both Komeito and the LDP.

It was Soka Gakkai members who originally formed Komeito in the mid-1960s as a way of achieving the “Buddhist democratic” political aims of its adherents.

After attracting criticism as an apparent breach of the constitutional separation of church and state, ties between the two groups were officially severed in 1970. However, most Komeito politicians continue to be Soka Gakkai adherents, as do a large proportion of its nationwide support base of over 6 million voters.

A “mutual dependency” exists between both sides of the LDP-Komeito coalition, according to a paper by academics Ko Maeda and Adam P. Liff published by the Japanese Journal of Political Science. Komeito’s supporter base of loyal, largely Soka Gakkai followers offers “unique advantages” and “benefits that would not be easy for any other party to replicate” as an effective junior coalition partner for the LDP.

This allows Komeito to “punch significantly above its weight in Diet seats when it comes to intra-coalition negotiations over policy issues about which its supporters care deeply” — issues that resonate especially with Soka Gakkai Buddhist teachings such as social welfare support and maintaining the war-renouncing Constitution.

While the relationship between Soka Gakkai and Komeito makes the widespread connection between politics and religion in Japan wholly apparent, it is still unclear how much of an influence the Unification Church has wielded over the political world since it arrived in Japan in the 1960s.

In the wake of Abe’s death, a former chairman of the Unification Church said that Abe’s grandfather, former Prime Minister and LDP leader Nobusuke Kishi, enjoyed a close relationship with the organization’s founder, Sun Myung Moon.

Police reports indicate that Yamagami was aware of this relationship, believing that it was Nobusuke Kishi who originally brought the church to Japan, and that this influenced his decision to target Abe.

Commentators have spoken of the shared arch-conservative ideological perspective underpinning the relationship between Nobusuke Kishi and Moon. The arrival of the church in Japan roughly coincided with Moon’s formation of the International Federation for Victory over Communism, and as an avowed anti-communist himself, Nobusuke Kishi was known to sympathize with the group.

In a video meeting with Unification Church affiliate group the Universal Peace Federation recorded last year, Abe said, “I appreciate the UPF's focus on family values,” before urging those assembled to “be aware of so-called social revolutionary movements with narrow-minded values” — a reference to the movement to legalize same-sex marriage.

While far from the top of the general public’s list of priorities, political opposition to issues such as gender-neutral language, LGBTQ rights and the use of separate surnames for married couples chimes closely with the fundamental teachings of the Unification Church. Hence the organization’s ties with more conservative elements of the LDP — who often also enjoy ties with various Shinto organizations such as Shinto Seiji Renmei — and, to a lesser extent, figures inside the Democratic Party for the People (DPP) and other opposition groups.

DPP leader Yuichiro Tamaki has admitted to receiving a donation from the former president of a newspaper associated with the church, while Kenta Izumi, leader of main opposition Constitutional Democratic Party of Japan, confirmed that certain lawmakers inside his party also had ties with the group.

“Religious organizations of all kinds have deep and sustained ties with politicians of every stripe by the way, not just the LDP and Komeito, but even the Communist Party,” McLaughlin said. “Much of it is quite benign. But it's a blurry line between what we might call religious and other engagements that are ideologically driven.”