* Japanese: This is the most common language used, especially if the Filipino speaker has some knowledge of Japanese.
* English: English is widely spoken in the Philippines and is often used as a common language between Japanese and Filipinos.
* Tagalog: Tagalog is the national language of the Philippines and is understood by many Filipinos. However, it's less likely that a Japanese person would know Tagalog.
* Other Philippine languages: Depending on the region and the specific Filipino person, other Philippine languages might be used.
It's important to remember that there is no one-size-fits-all answer. The language used would depend on the individual speakers and the context of the conversation.