Takashihe, Yuuhan wa Dungeon no Okudesu
タカシヘ、夕飯はダンジョンの奥です
Takashi, living a solitary life, awakens to discover he has been moved to a dungeon filled with monsters. A breakfast, likely prepared by his mother, and a letter from her are placed before him. The letter includes a single sentence. His journey starts from this point.