Like father, like son, huh...
|― Isanari Uesugi|
He has a distinctive golden, spiky hair and is mostly seen wearing a sunglass on his forehead. Fuutarou five years ago also shared similar facial traits to Isanari.
Isanari has a wild character. Fuutarou five years younger is said to share the same personality as his father, notably both were bad at studying.