This is a Guerrilla Marketing of a collection of students at Our Lady of Fatima to promote health awareness and encourage people to quit smoking. It was staged in public to make it look unconventional and more appealing to the targetted audience.
When we say Guerrilla marketing, it is a method of creating advertisements with minimal or too little budget to spend but requires intensive immagination to draw the attention of its target market. This is usually being done in streets or public places - Wikipedia.org
For additional proof, you can visit the social media account of the actress, Marjorie Drilon.
Update#1: DiversityHuman received a note from April Mae Cenita, a BSBA Major in Marketing Management at Our Lady of Fatima University (OLFU), confirming the veracity of the content of this article. In addition, she attached a screenshot of the message from the actor "Dave Hernandez Santos" stating that the video was created for the anti-smoking contest in the said university.

Update#2: Marjorie Drilon Issued an Official Statement over the wrong judgment and name calling of the netizens on Facebook. She is very disappointed with the behaviors of her online bashers. Drilon pointed out that the video campaign was done on purpose. It was not a real marriage proposal. (Read Marjorie's full statement)
Update#4. Know the team behind this successful wedding proposal video who also advocates anti-smoking campaign in the campus