Hanazono Ikkakujuu: Samusugi Isekai o Haru ni Shimasu!

Karakida Yasuko, known as Anko, is a high school student with a passion for growing vegetables. She treasures an antique clock decorated with a glass unicorn, but one night it shatters into pieces. In its place appears a young man named Ouki. He says he comes from another world, and enters Anko, saying "I can breathe here," and the two begin their strange life together! But then one day, when Ouki takes his eyes off her for a moment, Anko is transported to the other world... In a different world that has turned into winter, the adventure of vegetable nerd Anko and the next king Ouki begins. https://ebookjapan.yahoo.co.jp/books/724671/