I'm a kdrama, dorama and lakorn lover. Instead of telling you kdramas light-hearted dramas (cuz probably lots of viewers here could recommend you tons of it) would probably suggest, you could try Thai Lakorns that light to watch.
U-Prince Series: -All U Prince series were cute-, but here are my most favorite: The Handsome Cowboy, Badly Politic, Ambitious boss, Single Lawyer, Playful Comm-arts
Senior Secret Love Series: Bake Me Love, Honey Puppy Love 1
Ugly Duckling series: Perfect Match, Boy's Paradise
If my taste is same as yours, you'd probably will get addicted just like me. ^_^