Sweeet dreams- personally hated it, but female lead has a crush on this celebrity.
A love so beautiful- from what I remember , it has a plot very similar to playful kiss.
What's wrong with secretary Kim- self absorbed CEO, falls in love with his long terms secretary, who's quitting.
Strong woman bo dong soon - female lead ( who has super strength) has a crush on n her childhood friend, while another guy has a one sided crush on her. She comesto grips with her self, while trying to catch a criminal.
Boys over flowers/meteor garden-rich and spoiled boy falls in love with lead,gradually they fall in love
Love me if you dare- criminal psychologist, emotionally detached (think of him as Sherlock), falls in love with his assistant while solving crime
Descendants of the sun-only one sided for a little bit, soldier falls in love with a doctor, and they basically be a doctor and a soldier( not in a war though) through tough circumstances. I love the main lead, he's really kind,he gradually persuades the doctor to be in a relationship with him.
Empress ki/ the kings woman-if you want to try long historical ( not anything like playful kiss) strong female lead, in a love triangle, oso obvious one sided love.
Healer- a courier ( who basically does anything for money,falls in love with a reporter. One sided for a bit.
LI think there are loads out there, honestly I don't watch dramas like playful kiss a lot, so these series are a mixed bag... and not school dramas unfortunatel. Anything with romance is at some point bound to be one sided., so I just listed the ones I've watched...but I hope you find something you like!