Based on the document, the key named characters are:
Alex: The protagonist. He is a lumberjack from another world who is summoned by the goddess Luna to defeat the Demon Queen. His class is "Magical Girl" which causes some tension. Over the course of the story, he befriends Fufi and Merumeru.
Fufi: A flamingo who forms a contract with Alex. She serves as his familiar and guide in this new magical world.
Merumeru: A young slime girl that Alex rescues. She has powers over water and pipes. She joins Alex's party along with his clockwork dolls.
Luna: The goddess of cuteness who summons Alex to this world and charges him with defeating the Demon Queen.
Lily, Rose, Edelweiss: Alex's clockwork dolls that he animates to help defend in a tower defense game dungeon.
Demon Queen: The main antagonist that Alex has been summoned to defeat. Not much is revealed about her.
Bob and Martha: An elderly farming couple that take in Alex, Fufi and Merumeru for a time when they are fleeing from barbarians.