From Lezhin:
Having lost all contact with his sister, Shiyoung, a worried Shion sets out to see what is wrong by arriving in Australia, where his sister was staying. While staying at the share house his sister was living, he starts to sense that the people there have something to do with his missing sister.

Original Webtoon:
Lezhin, Bomtoon
Official English Translation (Lezhin)
Official English Translation (Copin Comics)