Dungeon Master wa Shinken Shoubu ga Shitai no ni!

For the sake of world peace, an explorer ventures into dungeons. A dungeon master thwarts him at every turn. The two battle repeatedly, and time passes. The explorer's adventures continue, and he has grown into a young man. The dungeon master, too, has grown remarkably. Her ample bosom, peeking out from beneath her clothes, is now undeniably prominent.