Life in the future after returning from another world

This story is about Ryu Amagi, a 16 year old high school student that has died on a accident while saving a dog. Due to unknown reasons he was then reincarnated into a body of a baby however its not just any baby, in fact its not even human rather it was a silver wolf beastkin. But it appears his parents died due to a monster attack to their carriage, but a passing by great sage managed to saw him carefully hidden in the carriage. And for over 13 years he was under the tutelage of the great sage, teaching him everything the great sage knows. but when it was exactly Ryu's 13th birthday the person that was taking care of him dies of old age.... Years passed since the great sage's death, news upon news about the great resurrection of the Demon Lord and the Hero summoning began to spread everywhere reaching far and wide. It managed to caught the attention of Ryu. he still vividly remembers the last words of his late master. 'Live for yourself, use everything that I have taught for you for yourself' and thus under those words, Ryu decided to use the knowledge and power he was taught with for the good of others...just like what he did in his old world. Ryu then hurriedly took off to the Royal Capital, where the rumoured Hero was summoned. 'if I were to help the Hero to subjugate the Demon Lord, I will be able to help alot of people' it was a naïve thought but it was his decision nonetheless. He managed to join the Hero's party after learning the rumours were true. and with that, he began to help the Hero fulfill his destiny. but to his surprise ,the Hero that was summoned to the Royal Capital was not a Japanese person, instead it was a resident of this world. Although he was expecting it to happen due to his past life's hobby of reading isekai light novels but to his disappointment it didn't happened, nevertheless he will still support the Hero with all his got. 3 years It took Hero's party 3 years before they can finally fight in the Demon Lord's Castle and confront the Demon Lord himself, and in that span of time Ryu managed to caught wind of a piece of information regarding and it says this spell was written in the Demon Lord's diary. Ryu rejoiced although he did die in his old world, it is not without regrets...his family, his friends, and...the girl whom he loves...all these years he could not get them off his head he wanted to see them badly again but that hope was lost....however this time, this piece of information managed to sparked hoped inside him once again, hope that he can see them again.