Adult

Synopsis
    John was just an average, everyday old man. He had always worked hard, had a wife, kids, and family. He had lived what most would call a good life.
    Then one day, at a crosswalk, some kids were not paying attention and tried to cross. A truck was barreling down the street, and John didn't hesitate and jumped in front of the kids and threw them out of the way, along with throwing out his back. The truck slammed into him, and the world went black.
    When he awoke, he found himself in a circular room, golden and silver lights flashing around the floor. Ten doors were lit up on the wall behind him, and a man was on a dais in front of him, head looking up, arms out wide like some type of showman.
    "Welcome, kids, to your new life as a DEN protagonist. You will be competing against other groups in various anime, vide- wait, who are you?"
    "My name is John. Who are you? And what is anime?"
    Follow our new protagonist while he ventures into new worlds he had never even heard of before and tries to survive.
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    Borrowing this scale that I saw some other authors use on this site for R-18 content.
    Hearts will be in the chapter title.
    Chapter Ero-meter:
    ❤ - A bit of explicit content
    ❤❤ - Around half a chapter of lewds
    ❤❤❤ - WAIT?! IT'S ALL F***ING LEWDS?!
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    Follow me here for progress updates on upcoming chapters.
    Discord for discussion of my novels, or just hang out - .gg/ZrKJJ5qDrh
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    Things to note about this novel.
    He is an old man, and they didn't give him a young body; they just did some minor cosmetic and physical changes. He will get some bonuses as he progresses, but he will never be the 18-25-year-old ripped MC, even if he replaces an MC who is that way. (But maybe he will be like Silver Fang from OPM, who knows)
    He has no idea about anime, video games, or anything about the worlds he is entering. He is just armed with some knowledge from living for 80 years. I'll be forcing some canon scenes in these worlds, but there is a reason for it.
    MC will be hopping worlds fairly frequently.
    He will not be OP out of the gate; he will be training and recovering a lot.
    This will probably be a slow burn for smut. I plan on keeping the harem down to no more than 2-4 per world, as that will be a difficult enough challenge to keep up with once the story develops. I reserve the right to change my mind on this, though =)
    Current worlds as of Chap 100 that John has visited
    High School of the Dead - AU Teacher
    The Great Cleric - Replaces MC
    Starcraft - Replaces MC
    Infinite Frontiers - My own Sci-Fi OG work, 43 chapters of this NovelFire are here so far
    High School DxD - AU - The Kuoh Academy Principal
    Upcoming Worlds as voted on by the readers
    Warcraft 3 - Replaces Arthas
    RE:Monster - Replaces the old goblin
    My Hero Academia - AU - 2nd or 3rd year teacher
    Konosuba - AU - Replaces MC
    Battletech 3049 - TBD. Will be voted on soon where he starts
    The Wrong Way To Use Healing Magic - TBD
    1-2 chapters a week, approx. 2500 words each.
    I am active in the comments, and I want your feedback. Good, bad, or ugly. Preferably constructive, as I can't do much with "This is a terrible novel. Dropped."
    4-5 stars are always appreciated.