Contract Love From Today (2021)

Both are miniseries and about high school romance.
Both have supposedly love triangle

One is gender bender

Both are high school drama with short duration episodes.
Somewhat similar concept
one has kpop idol and other is about becoming kpop idol

As the season 1 is recommended I am recommending the second season as well. The actors from the drama had cameo appearances in the drama. Both are high school web drama. Bith from whynot

main leads are also a couple in shooting stars.
Both enemies to lovers.
Main leads are of same age
Female lead is working in entertainment industry
Bickering couple

Mitsuru Adachi's masterpiece of a short story collection "Short Program" was made into a live-action drama starring the global boy group JO1. For the first time, all JO1 members will take on the lead role in one of the eleven carefully selected episodes. The episodes of this diverse youth romance drama are packed with various elements, such as music, sports, and action. Where will the eleven boys who are chasing their dreams go?