yes, your Yemeni friend requires a tourist visa to Philippines, the below documents are required:
Passport/Travel Document Valid for at least six (6) months beyond the intended period of stay in the Philippines;
Duly Accomplished Visa application forms;
Passport Photos (2 pieces);
Proof of bona fide status as tourist or businessman;
Confirmed tickets for return or onward journey to the next port of destination; and
Payment of Visa Fees