Japan Prime Minister Shinzo Abe feasted on bean soup and rice cakes at the humble home of Philippine President Rodrigo Duterte on Friday, and sampled the down-to-earth living of a volatile new friend who is shaking up the status quo in Asia.

With the backdrop of family photos, cups hanging from kitchen cabinets and clusters of used beer and wine bottles, Abe ate Duterte's favorite breakfast in Davao City and was given a tour of his creaky, two-storey house, including a bedroom featuring the mosquito net he sleeps under on most weekends.

Duterte's simple living is part of the man-of-the-people style that endeared him to the millions of Filipino voters who in May favored an abrasive city mayor over wealthy politicians on a largely Manila-centric ballot.

Abe's visit comes as the Philippines edges closer to becoming a geostrategic battleground, with China offering billions in loans and investments, as Duterte opts to befriend Beijing and avoid challenging its maritime claims while ramping up hostility towards historic ally Washington.

While Japan's allies in the West ponder how to deal with the hot-headed new leader, Abe has formed a close bond with Duterte during the four times they have met.

He is the first head of state to visit Duterte and arrived on Thursday offering a 1 trillion yen ($8.77 billion) aid and investment package aimed at boosting the flagging infrastructure of one of the world's fastest growing economies, in which Japan is a top investor, donor and trade partner.

The two leaders, both dressed in short-sleeve shirts, did not discuss business on Friday and were photographed mostly eating local delicacies.

Duterte's top aide, Christopher "Bong" Go posted images of their private breakfast meeting on his Facebook page.

"We also showed him how the President enjoys the comfort of his own bed, including his old and favorite mosquito net," Go posted.

Abe also became the owner of a Philippine eagle, named "Sakura", which is being treated at a local rehabilitation center after being shot and wounded by hunters.

He didn't get to meet Sakura personally, but was given a stuffed eagle toy instead, bearing a medallion engraved with "Sakura is adopted by Mr Shinzo Abe".