My Best Is Fair Prince (2021)

This is a spin-off drama of "The Prince of Guesswork", "Boku no Guesswork wa Oji-sama". "The main character is Arisugawa Ryo (Seto Toshiki), a planner at Pegasus Inc. and a history buff. In fact, Arisugawa has always had a crush on a certain person while resigning himself to the fact that it's a love that will never come true.