Soara and the house of monsters

Soara is a young orphan girl who was raised by knights and trained to fight against marauding monsters, but when she comes of age, she finds herself working with Kirik the dwarf, Architect of the Monster World, to build comfortable homes for monsterkind instead. First, The group builds a home for a thunder wolf and a mermaid, a pair of lovebirds who can't even touch each other. Then, they head off to the castle of the powerful and fearsome Demon Lord where they learn more about how the demon world came to be what it is now. The demon lord tells them about the woman who originally built his castle, and he asks for their help in finding her in order to build peace in their world.