Jester

Kiridere… or something like that? This term describes a person who typically appears dignified, serious, composed, and hardworking in public, but who suddenly becomes affectionate and displays a more tender and overly affectionate side when alone with someone they are interested in. They are serious and enthusiastic about their work and studies, so they walk with a strict, serene, and dignified posture, and a stern expression that gives them an unapproachable air.