This Trophy is Missable
Once again, along with other Trophies in this game that are missable, this one falls into the 'You didn't get it because you couldn't be bothered turning on the TV in your room' or perhaps didn't have enough money, which again should not be an issue.
Progress into the main story line, and on the way to school one morning you overhear students talking about the program on TV. The program runs every Sunday (your day off school) and you always start the day in your room right next to the TV. The game itself even tells you every weekend that you haven't purchased something and maybe you should listen to the show. Simply purchase 5 packages over the course of 5 weeks (time flies by in this game) and at the screen of the 5th one upon buying you'll receive the Trophy!