Novels of Various Types Across Time and Space

There are too many bad settings in anime and games, so they need to be changed. However, because the protagonist is a stupid young man, and this is not a cheat, the protagonist has to work hard. (I saw on the headlines what to do if a primary school student blocked the toilet, and then I had a sudden thought). There will be other fun things in the future, and you can also travel through time (I haven't seen some anime, I need you to talk about it)