There is a hole between Tien-feng's left and right cardiac atriums, so that he is frail; when his classmate struck him, Tien-feng did not fight back, but simply collapsed to the ground.
天風心臟的左心房和右心房之間有個破洞，體力不好，同學一拳打過來，天風沒回手，暈倒在地。