CasinoGui is a Manga/Manhwa/Manhua in english language, Crime series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

Gen Suzuki, a young man who grew up in an orphanage, is trying to live an honest life.
But when the cruel reality of the 10 million yen debt from her sister hits him, he decides to rob a Dark Casino.
What awaits him is the baptism of the underworld!