Both dramas have good looking ikemen actors. In Happy Boys they're serving coffee while in GiraGira they're hosts serving alcohol (and their looks) to women....
They have almost exactly the same premise of boys who are working at some place to learn how to make the world a happier place. They also have the same triple dynamic of a flashy host type, glasses type, and country-bumpkin type. Also, the chef actor from this show is in Beauty Boys Celebrity as well. On Crunchyroll the show is called Biyou Shounen Celebrity.