Huyao Xiao Hongniang

They are deeply emotional love stories between humans and beings from other realms. Main characters posses supernatural powers. They have fantastic world building rooted in Chinese literature and folklore. Huyao Xiao Hongniang has more comedy. Da Yu Hai Tang is more melodramatic. 

These stories involve the encounter and bonding between humans and spirits (yaos). They are cute, funny and eccentric. They mix action and comedy very well. Huyao Xiao Hongniang has more drama and romance. Luo Xiao Hei Zhan Ji is more lighthearted and only has subtle romance undertones. 

Chinese series <3. We are talking about two really different stories, but at the same time very similar with the whole theme of reincarnation and demons, etc. Huyao is translated into Japanese, Yagouai is not. but leaving aside that I think that if you liked one you'll like the other (Huyao is more comedy / romance and Yagouai is more drama / romance) 

There are some interesting similarities like: - The characters profile/attitude: Ex: The main character Susu have personality similarities with TMI's Index, both of them are underage girls with a huge occult power. Yuechu is also similar to TMI's Touma. - Introduction similarities: Funny or not, the Main characters of both TMI and Huyao Xiao Hongniang met each other by accident. - Timeline similarities: Like mentioned before, the Main characters of both animes "discover" their true power, leading them to a successful journey. 

Both shows focus on cultivation and the idea of past lives. Both have good Fox MCs  

The stories are about a female and a male character that are in love or fall in love with each other Both of those stories follow the common troop of cultivation, martial art/tecniques, spirit power etc. The enemies/villains are the typical type that want something from the MC and will try anything to do to aquire it. 

They both are great Chinese Anime: - same genre: Action, Supernatural, Comedy and Drama - both stories are entertaining, exciting and quite unpredictable - similar characters: both male protagonists are strong and use miraculous power, female characters are similar too Huyao Xiao Hongniang is more focused on comedy (especially season 1). If you like one of them you probably will not be disappointed of the other show. 

Both are stories involving Chinese mythology containing characters with animal attributes and special powers.