Russian Transfer Student Who Can't Speak Japanese is a Manga/Manhwa/Manhua in english language, ROMANCE series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

In the second year of high school, Iori Kagami is a boy who doesn’t stand out. Some of the students dislike him because of their impression of his twin sister, Shiori, who is famous as the perfect idol of their whole grade. With special permission, Iori lives in a US military base in Japan and works part-time as an interpreter. While working with Cheena, Iori’s talents are revealed and he starts to look around at the people around him. This is a story about how Iori’s talents are revealed when he gets involved with Christina.