Celestino has long brown-taupe hair that is always pulled back into a ponytail, save for a shorter strand of hair that always sticks out. He also has sideburns. He has thick eyebrows and light green eyes. His face is very angular, with a square chin.
When he was younger, he had longer, thicker hair that was worn loose under a blue headband.
Celestino is usually quite cheerful, both on and off the ice. He tends to be a bit rigid in making decisions for his skaters' programs, rather than bending towards their opinions.
Celestino is Phichit's current coach who is very supportive of him and he is confident in Phichit's abilities. The two have quite a casual relationship, and Celestino sometimes takes videos of Phichit skating. Phichit sometimes refers to Celestino as Ciao Ciao.
Celestino works alongside Satsuki as Phichit's coach where the two of them are commonly seen together during Phichit's performances and at the kiss and cry.
Celestino was Yuuri's coach when he lost in the Grand Prix Final. He noticed that Yuuri lacked confidence and wanted to encourage him. After Yuuri cut off contact with him, Yuuri tried to avoid seeing him again. When Yuuri calls him about selecting his free skate music, and tells him that he will do his best to win the next Grand Prix Final, Celestino is pleased, and tells him that that was what he was hoping to hear after Yuuri's loss the previous year.
Celestino is very supportive of Yuuri, comforting Yuuri when he was down and bringing Yuuri to the Grand Prix Final banquet in the previous year. He bears no ill will towards Yuuri when he chose Victor as his coach.
Celestino coached Jean-Jacques at some point, though the partnership did not last long, as the two of them had clashing personalities. After Jean-Jacques' free skate at the Barcelona Grand Prix Final, Celestino mentions that he is proud of Jean-Jacques' achievements.
- "Ciao Ciao!" (to Yuuri Katsuki)
- "Yuri never had much confidence in himself." (to Victor Nikiforov about Yuuri Katsuki)
- "Unfortunately for you, it won't be Yuuri [Katsuki] who wins the Cup of China. It will be Phichit Chulanont." (monologue directed to Victor)
- "Yuuri [Katsuki] isn't used to being the one to beat." (to Phichit Chulanont)
- "Massimo!" (about Phichit)
- "A pupil's accomplishment is headier than any wine." (about Jean-Jacques Leroy)
- "Phichit, use your performance to intoxicate the world." (monologue directed to Phichit)
- It is likely that Celestino has a low alcohol tolerance.