Mr. Higurashi

 was the late son of Grandpa and Grandma Higurashi, husband of Mrs. Higurashi, father of Kagome and Sōta, and posthumous father-in-law to Inuyasha.

History
He proposed to Mrs. Higurashi by the sacred tree after they had a fight. He died in a car accident before Sōta Higurashi was born, and the rest of the family moved to Higurashi shrine.

Trivia

 * He never makes a physical appearance in the series.