When Philippine leader Rodrigo Duterte arrives in Tokyo today for a three-day visit, his hosts will be watching for clues on how Manila wants to do business.
Japan is the Philippines' top provider of development aid, top foreign investor, top trading partner and, together with the United States, a major source of maritime security assistance.
But Mr Duterte's visit comes just days after he cosied up to China on his trip to Beijing, where he announced a "separation" of ties from the US, which has criticised him for a lethal anti-drug campaign. He later said he was not cutting diplomatic ties with Washington.
Tokyo, meanwhile, is a staunch US ally and has frosty, albeit thawing, ties with Beijing over a territorial dispute in the East China Sea.
Despite last week's political bombshell, observers expect Japan to preserve its strong ties with the Philippines and perhaps even play "peacemaker" between Manila and Washington, given its strong ties with both.
Mr Duterte has previously expressed appreciation for Japan's role in economic development in the Philippines and support for rule of law in the South China Sea, said Professor Heng Yee Kuang of the University of Tokyo's Graduate School of Public Policy.
Also, Japan's Mr Fumio Kishida was the first foreign minister to be received by Mr Duterte on his home turf of Davao, the largest city on Mindanao island. During the August visit, they discussed enhancing their defence ties.
"Tokyo will continue its emphasis on capacity building for Philippine maritime security and stressing to abide by rule of law and the South China Sea ruling," Prof Heng told The Straits Times.
He was referring to the July decision by an international arbitration tribunal that emphatically favoured Manila over Beijing's claims to large swathes of the waterway. Tokyo and Washington have been critical of Beijing for rejecting the ruling, and China has repeatedly accused the two allies of interfering.
Research fellow Ippeita Nishida of the Tokyo think-tank Sasakawa Peace Foundation said the Japanese government needs to "re-confirm with Mr Duterte that Japan, too, is a stakeholder in keeping the rule of law, especially at sea".
Local media reports quoted sources saying that Japanese Prime Minister Shinzo Abe will likely reaffirm Tokyo's stance on maritime security, given its own dispute with Beijing. But Philippine presidential spokesman Ernesto Abella yesterday said the main agenda "will not be political, but economic".
He said: "So if it's (the South China Sea) referred to, it will be on the sidelines. If there's anything at all, it may be exploratory. But at this stage, it's not part of the agenda."
Mr Abella added that the two leaders will be discussing "security, economic and defence issues" during Mr Duterte's trip, which is meant to "continue the Philippines' efforts to bolster strategic partnerships with its Asian neighbours".
Mr Abe will reportedly sign an agreement tomorrow to supply two new patrol boats to the Philippines, adding to the deals already concluded to equip Manila with multi-role ships and long-range surveillance planes.
Other issues likely to be discussed include Japan's overseas development assistance programme for the Philippines, including its aid against terrorism in conflict-rife Mindanao. A further 5 billion yen (S$67 million) in loans is also reportedly on the table at the visit, and is meant to help Mindanao farmers grow their businesses and improve their productivity.
Mr Abe will hold one-on-one talks with Mr Duterte at his Tokyo residence tomorrow, following a larger, more formal meeting with senior officials.
Mr Duterte will wrap up his visit with a call on Emperor Akihito on Thursday.
• Additional reporting by Raul Dancel in Manila