So from what I remember, it's about a Japanese guy being transmigrated into a body of a white hair boy, and an old man(elf?) finds him in a dangerous forest that no humans go into. That old man has many wild/dangerous familliars by his side, that humans consider them very dangerous and don't ever go near them. That old man raises the boy and gets along with all the animals especially the White Wolves, he then forms a bond with one of the pups of the big wolves and go outside of the forest to explore the world with the familiar and a bird. That's all I remember, I hope that's enough for all of you to recognise the novel/manga
Is it Mofumofu to Isekai Slow Life o Mezashimasu? I only follow the manga, dunno about the novel. Edit: I don't think the novel translated yet..? I can't find the novel here in NU