Doujin Fever!! Train Assault!

An ordinary office worker's life is shattered when he discovers his girlfriend with another man. Unable to forgive the betrayal, he cuts both of them out of his life, but his anger and disappointment never faded away. In an attempt to never cross paths with them again, he begins taking a different train home. There, by pure coincidence, he encounters Hibiki, the sister of the man involved in the affair. The encounter soon leads him down a path of lusftul revenge.​