異世界帰りの最強テイマーはモンスターに支配された現実世界で自由に生きながら冒険することにします (Associated Names)

I, a former hero who returned from another world, spent my days idly as an unemployed person. But one day, the world changed drastically. Monsters flooded the city, and everyday life quickly fell apart. A giant tree grew and mysterious buildings appeared. The earth was transformed into another world. In this completely transformed world, while…