Kiyotaka Ayanokōji is daddy (@fw.fatherayanokoji)

Kiyotaka Ayanokoji Personality Classroom Of The Elite - Anime Personalities

Kiyotaka Ayanokōji/Relationships, You-Zitsu Wiki

Kiyotaka Ayanokoji and Kei Ayanokoji/Karuizawa by Lodestar1 on DeviantArt

Professor Ayanokōji, You-Zitsu Wiki

Ayanokoji Met His Father, White Room Revealed

Ayanokoji when he was kid, during the time he traveled to New York with his parents. And you also can see a hand holding him. I guess it's his father hands holding

Ayanokoji finds out who the father is : r/ClassroomOfTheElite

Who is more intelligent or will win against each other solely on their wits, Ayanokoji from Classroom of Elite or Lelouch from Code Geass? - Quora

Classroom Of The Elite Class S - Chapter 4 : Father's Teachings - Wattpad

It kinda amazes me how Chabashira created her own fiction about Ayanokouji's situation without even ever having talked to his father. : r/ClassroomOfTheElite