"It's always on my mind because I miss you."
Here's a breakdown:
* "Plgi" is a shortened form of "palagi," which means "always" or "constantly."
* "k sa isip ko" means "in my mind" or "on my mind."
* "kasi" means "because."
* "miss na kita" means "I miss you."
The phrase conveys a strong sense of longing and affection for someone.