Elf no Oshiego to Sensei

One day, the human world is suddenly connected to the fantasy world. A parallel world inhabited by Elves. Japan received twenty young Elf women as students. The aim is to build trust and understanding between humans and elves. Kobayashi Hiroki, is a man asked by the government to become a teacher who teaches the Elves. After going through various coincidences, Hiroki unexpectedly dated one of the Elves named Laranoa. They keep this dating relationship secret from others. Then what happened to them? Can they keep their relationship secret? (Source: Translated and Edited from Nekopoi)