@
mahtan
I can't think of many manga dungeon core stories, but there's quite a few book ones. Probably the best (in my opinion anyway) is the Divine Dungeon series by Dakota Krout. First book is called Dungeon Born, it's on sale right now, or free if you have Kindle Unlimited. A japanese webnovel that's being translated is The Lazy Dungeon Master, which won't cost you anything, but doesn't have the complete story arcs of a published book and the translator is kinda slow.
As for lolis, they look like children (by definition), and this manga is tagged for ecchi, romance, and harem, which means they will almost certainly be sexualized.