Toshiya wears brown-rimmed glasses and a red bow tie. He also wears a grey shirt with "Yu-topia" written on the lapels and a green waistcoat. He has dark grey hair and usually wears it parted in the center. His eyes are usually closed, though they will occasionally open when he is surprised.
Toshiya is a cheerful individual who likes to make jokes. Later on, it is revealed that he becomes rambunctious when drunk, a trait he passed on to Yuuri.
Toshiya is Yuuri's father. He is very supportive of his figure skating career, although he does not know much about figure skating.
Toshiya is Hiroko's husband. They run Yu-topia Katsuki together.
Toshiya is Mari's father. Mari works with both her parents in running Yu-topia Katsuki.
- "Wow, you look just like your Mom, Yuuri." (to Yuuri)
- "You've gained weight easily, ever since you were a boy, but what can you do." (to Yuuri)
- Toshiya does not know much about figure skating, as he is more of a soccer fan.
- Toshiya's supports Sagan Tosu, which is based in Saga, where the Katsuki family stays. In Episode 1, he appears with a Sagan Tosu towel on his shoulders when a customer switches the television channel to soccer.
- The toshi (利) in Toshiya (利也) is also the ri in Yuuri (勇利) and Mari (真利).
- Crunchyroll incorrectly romanizes his name in the first episode as "Toshio".