I found myself getting bored after episode four, just because I realise that each episode has the same formula: character faces a problem, try to solve them and at the end, the character will show how determined they are to solve the problem by sacrificing anything they have. Therefore the plot is very predictable and did not give me any excitement at all.
The characters - especially the main character - is the type of character I will always avoid when watching or reading a story. He's just very annoying, or everyone is rather annoying in general. However, I told myself to be unbiased and just try to watch everything first. I thought it would change my mind if I finish every episode, but nothing changed.
However, I understand why my sister would recommend this anime to me. It's interesting to know the background story of each 'yokai'. If the story focuses more on how each being turns into a 'yokai', then I guess the anime will pique my interest.
I heard that there is season two, but I do not think I would continue watching this series. It did not captivate my interest enough for me to watch another journey of the story.