Reverse Tower Dungeon

Reverse Tower Dungeon is a Manga/Manhwa/Manhua in (English/Raw) language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.com fastest updating comic site. The Summary is

The main character, Tsurugiya Daichi, is an aspiring novelist. He doesn’t do very well, so he works part time as he continues updating his webnovel. While doing so, he has a theatrical reunion with his high school friend, Himari Hinomoto, whom he separated from on less than ideal terms in the bookstore in front of his work. In that moment, as if their meeting was the trigger, the world gets turned upside down. Magic circles appear, skyscrapers sink, and the interiors of buildings are “reversed”. What’s more, the monsters from Daichi’s novel attack… Can Daichi and Himari escape safely from the “inverted” tower?　A web-comic fantasy with unpredictable twists and turns!