During the arrest, authorities recovered estimated illegal drugs valued at P340,000, along with a digital weighing scale, two evidence pouches, and a tricycle.
The 22-year-old tricycle driver faces drug possession charges under Section 11, Article II of Republic Act 9165, also known as the Comprehensive Dangerous Drugs Act of 2002.
Officers transferred the 15-year-old minor to the Bahay Pag-asa Youth Center for temporary protective custody and a formal assessment of discernment.
Under Philippine juvenile justice laws, minors involved in offenses receive specialized protective handling rather than adult criminal processing.
The Mandaluyong operation was one of two anti-drug actions in the capital region that resulted in the arrest of two adults and the recovery of a combined 72.4 grams of suspected shabu valued at P492,320.
In a separate buy-bust operation early Thursday in Taguig City, police arrested a 26-year-old suspected street-level drug dealer and seized 22.4 grams of suspected shabu worth P152,320.
NCRPO director Maj. Gen. Anthony Aberin affirmed that police forces will sustain anti-drug operations across Metro Manila while adhering strictly to statutory safeguards for cases involving juvenile offenders.