Isekai Meikyuu no Saishinbu wo Mezasou

An ordinary kid by the name of Aikawa Kanami winds up in a fantasy world operated by RPG video game rules—but this isn't good news. He awakes in the bowels of a gargantuan death trap called the Dungeon. Narrowly escaping thanks to his grit, cunning, and newfound arsenal of magic spells and skills, he wants nothing more than to get back home to Earth and the invalid sister who needs him. His only lead? It's said that whoever makes it to the hundredth and final level can have any wish granted. In his desperation, Kanami cooks up the most efficient means of clearing the Dungeon and lies his way into a partnership of expediency with an aspiring swordfighter who's rubbish with the blade but unbelievably skilled at magic. Kanami's cool determination, however, is soon put to the test when he and his new comrade are faced with a surprise boss fight. How far will he go in order to emerge victorious?

(Source: J-Novel Club)