パラダイスシフト ～ある意味楽園に迷い込んだようです～, Paradise Shift Aru Imi Rakuen Ni Da Yodesu

A simple gamer becomes the strongest high schooler — a dreamlike modern fantasy! One day, the world was rewritten into something straight out of a fantasy game!? Yūki Sasahara, an ordinary high school student who loves games, was living a peaceful everyday life when suddenly the laws of the world changed, and his reality shifted into something like another world. In this transformed world, Yūki uses his game knowledge to quickly rise as a powerful figure! And during a “summoning experiment” meant to call forth artifacts from another world… the one who appears is a beautiful elf girl!