Heungmakdeurui Joryeonsa-ga Doeeotseumnida

When veterinarian Yoohee Han dies early, a grim reaper sends her into the world of a novel she once read to live out the rest of her time as the side character Alexa. She uses her knowledge of the novel (and of animals) to take on a more prominent role as the trainer of Isildus, heir of Terrecion, a wolf shifter who will remain in animal form until his 16th birthday. She becomes a beloved advisor in Terrecion castle, and her actions change the fates of other characters. How will little Issy feel about her when he becomes human?
(Source: Tapas)