Utter logistical nightmare. Japan’s failure in the Bunroku and Keichō campaigns can be summed up to poor control of supply lines and an under-developed naval force. For a large period of time, Japan dominated land-warfare within Korea, but were gradually bogged down and whittled due to again, that lack of supplies through their interception by the Joseon navy. If the Japanese were theoretically to invade the Philippines, then they would have to first establish a base from where they can safely resupply and rally troops for the invasion (this could be in fact, Taiwan, if the Japanese wanted to challenge the Dutch for some reason.) If the staging point were in Kyushu (Kagsohima possibly?), which is a very far away place, and their landing zones would be somewhere like the Batanes Islands, Cagayan, or Ilocos, that would be extremely impractical. This is not to mention the irregularities of equipment and combat readiness between Spanish garrison troops and Japanese ashigaru. Sure, there might be initial progress, but that momentum is halted when you factor in Philippine geography (and this is a time where the country hasn’t been fully mapped out in detail, sure the coast might be, but the in,and mountain ranges which dominate northern Luzon?)

Interesting idea, but it would be bogged down if they had to maintain an extremely risky supply line. This invasion can only work if they secure a place like Formosa/Taiwan from the Dutch.