I liked the first series Hoozuki-san Chi no Aneki it had a weird premise but great characters and the constant teasing of Gorou by Haru was funny but sweet.

This series is a sequel to that and my god what the hell happened? Seriously?

Story: 2/10
There is an imouto now. That is mostly it...
The author does try to put more depth into the story later on but his god damn fetish just keeps getting in the way of actual plot. It is kinda like she wanted to make a hentai but couldn't.
Once Volume 5 begins the author starts to completely ditch a story and it just becomes a day to day story. The author seems to forget the plot thread she left and just doesn't care anymore

Art: 6/10
To be fair the art is really good and is most definitely improved from the first series. I do find it difficult to differentiate between the sister and Mizuno at certain panels though.
However, once volume 5 begins the art style changes dramatically probably and it honestly it is very jarring.

Character: 2/10
If you loved the characters in the first series then you honestly might just hate them now.
Gorou has become much more of a pervert now to the point where you don't root for him anymore...
Haru has become so drastically different from the first series that I honestly thought it was another character. Her tease in the first series was weird but funny but in this series she is suddenly much more slutty now...
Aoi is the new character and the imouto and she is competing with Haru on how much they can jack of their brother Gorou...
Any other returning characters are just their personality from the first series dialled to 11 or turn up to 500%. Except Mizuno who is probably the character from the first series who is still as good as you remember her from the first.

Enjoyment: 4/10
There is some fun in the series but it is on the border of just being an hentai so don't read this series in a room with others...

Overall: 1/10
Just what happened...
Seriously...
What is wrong with the author...
If you read the first series Hoozuki-san Chi no Aneki then don't waste your time reading this series cause it is no where near as good as the first one. The author doesn't care anymore so you shouldn't either