With total assets of 74.5 trillion yen ($670 billion), the life insurer, also known as Kampo, is one of Japan's biggest institutional investors and a major player in the world's third largest stock market.

The firm plans to triple the portion of environmental, social and governance (ESG) investments in its domestic stock portfolio to around 100 billion yen over the next couple of fiscal years starting in April, Chief Investment Officer Atsushi Tachibana told Reuters.

Kampo is taking a radically different approach compared to conventional ESG investments, he said.

In recent years many ESG investors have focused on "somewhat superficial criteria" such as the percentage of female managers, the average rate of paid leave taken by employees, or a company's carbon emissions, he said.

Kampo tries to identify companies that it believes have a technological edge to solve global ESG issues and meet U.N. Sustainable Development Goals (SDGs), a set of 17 goals and 169 targets aimed at resolving social, economic and environmental problems troubling the world.

"We look to what extent companies' exposure to businesses or products that will contribute to solving ESG challenges are driving their growth," Tachibana said.

"That's not something you can find in their public disclosure. We try to get an estimate through the 300 to 400 meetings and factory visits our analysts have with companies annually," he added.

Based on that strategy, Kampo's ESG portfolio looks very different from other ESG funds, he said.

RECYCLER, LED HEADLAMP MAKER

The top 10 holdings in Kampo's ESG-focused growth stock fund include FP Corp, a leader in manufacturing and recycling disposable food containers used in supermarkets, and Koito Manufacturing which makes LED headlamps for cars.

The fund does not include common ESG names such as Toyota Motor, Sony and KDDI, which have heavy weightings in ESG indices such as MSCI Japan ESG Select Leaders and FTSE Blossom Japan.

Since its launch last April, the returns for Kampo's ESG fund have beaten the benchmark Topix index by 2.5 percentage points, MSCI Japan ESG by 0.5 percentage points and FTSE Blossom by 2.7 percentage points, as of March 8, Tachibana said. Kampo is the insurance arm of former state-owned conglomerate Japan Post Holdings. The insurer has increased investment in riskier assets since it was partially privatised in 2015.

Previously, the firm has relied heavily on outside asset managers to oversee its mostly-passive stock portfolio, which rose in value to 2.118 trillion yen by September 2018 from 997 billion yen in March 2015.

It plans to double its in-house, actively-managed portion of the portfolio - which includes the ESG-focused growth fund and a high-dividend fund - to about 20 percent of total stock holdings, or about 400 billion yen, in the near future, he said.

As for Japan's stock market, he remained cautious despite a recovery since January.

"We expect the global economic slowdown to continue a bit more, so we don't plan to increase our domestic stock portfolio in the near-term," said Tachibana.

"That said, their valuation is cheap and I think they can be good investments in the longer term."

(Reporting by Tomo Uetake; Additional reporting by Hideyuki Sano; editing by Darren Schuettler)

By Tomo Uetake