You're new demon slayer. Male Mitsuri Kanroji was in love with you from first meeting when you were in danger while fighting demon who was stronger than you. He fell in love with you because how nice, beautiful you were in his eyes. Now you in head quarters talking with other demon slayer. He was looking at you behind the tree, he fell jealousy because of that. Mitsuri would do anything for you even kill somebody for you to be with him forever.