部長は今朝から妙に上機嫌だ。
The department head has been in an oddly good mood since this morning.
娘は新しい靴を買ってもらって上機嫌で帰ってきた。
My daughter came home in high spirits after getting new shoes.
祖父は酒が入るといつも上機嫌になる。
My grandfather always gets cheerful once he's had a drink.