Brotherhood. According to Sohu Entertainment Network, Ha Yi is the grandson of Mr. Haruichuan, a famous Chinese medicine dermatologist, and a descendant of Ha's Chinese medicine dermatology; Ha Gang is the grandson of Mr. Haruichuan, a dermatologist and chief physician of Beijing Andingmen Hospital of Traditional Chinese Medicine, and a famous dermatologist of traditional Chinese medicine. Both of them are the grandchildren of Mr. Harikawa, so Hay and Ha Gang are brothers.