Reincarnated As a Fish is a Manga/Manhwa/Manhua in (English/Raw) language, THRILLER series, english chapters have been translated and you can read them here. You are reading Reincarnated As a Fish chapters on www.mcreader.net, fastest updating comic site. The Summary is
On the verge of death from the betrayal of his trusted colleague, 'Lee Yoo Shin' sees a ray of light moments before dying. "Do you want to start a new life again?" When he came to his senses, there was a vast reservoir in front of him and his body had turned into a fish. Will he be able to overcome all the hardships and return to his family's arms?