My Friend the Doe, Noko-tan. Volume 1

Torako Kosi, a clever and intelligent girl and a role model, hides a terrible secret: she used to be a bully. She easily managed to hide under the mask of a beauty and an honor student until one day she encountered a strange creature with a long drooping snout... Upon closer inspection, Torako realized that it was a girl who had gotten tangled in wires with her horns (?!). She saves the doe, but from that day on, Shikanoko becomes a real nightmare for her, threatening to destroy her carefully crafted reputation.