Yakov Feltsman is the coach of Yuri Plisetsky, Mila Babicheva, Georgi Popovich and Victor Nikiforov. He is 70 years old.

As a coach, Yakov is very strict with his skaters. He dislikes it when Victor disregards his instructions, even when it is to his advantage. He is quick to lecture his students about their mistakes, a trait that he unintentionally passes on to Victor.

Yakov seems to be a fatherly figure towards Yuri, supporting the young skater in his endeavours, and going out of his way to find a separate coach to train Yuri for his free skate. According to Victor, Yakov would be willing to extend help to Yuuri, if Yuuri were to only hug Yakov.

(Source: Yuri!!! On Ice Wikia)

Yuri Katsuki makes his way to the Grand Prix ice skating competition as Japan’s top representative with his eyes on the prize. However, instead of celebrating, Yuri walks away defeated and ready to retire for good. But a run-in with champion Viktor Nikiforov and rising star Yuri Plisetsky ignites a new fire within him. With the two of them close by his side, Yuri will take to the ice once more.<br><br>

(Source: Funimation)

A side story manga was published as a bonus item included with the final Blu-Ray volume of the anime series, and follows Yuri Plisetsky and Otabek Altin the night after the Grand Prix Final.