Isekai Tensei... Saretenee!異世界転生…されてねぇ!

On the first day of high school, Yuuki Kousuke was killed while trying to help someone. However, that was not the end of his story. The old man he helped happened to be a god. As thanks, he lets Kousuke reincarnate into another world. He was overjoyed to live the life of those overpowered protagonists seen in his favorite isekai stories, however, when he came to, he found himself at the very same spot he died. This is the story of a protagonist living a peaceful life in the modern era with the cheat ability given to him by a god... not. The cat he ended up saving turned out to be a god too. (Source: MangaUpdates)