Yarinaoshi Reijô wa Ryûtei Heika o Kôryaku-chû

This anime based on a light novel and manga, adapts it faithfully and animates the characters and action scenes well. A lot of the criticisms stem from one thing: The age gap. To that I say: Read a damn book. Back then in novelty and royalty, political marriages and concubines' were extremely common. We live in a more refined society where we say no because we understand the implications and disgustingness of what they used to do back then with children. But that shouldn't mean we should shun a faithful adaptation for providing an accurate historical basis on a light-hearted non-serious, funny anime.