morning person; early bird
Describes someone who functions best in the morning and prefers waking up early. Often contrasted with 夜型人間 (night owl).
See also: 夜型人間
I'm a morning person, so getting up at 5 a.m. every day is no trouble.
朝型人間と夜型人間では生活リズムが大きく異なる。
Morning people and night owls have very different daily rhythms.