I just binged through the whole thing, and I must say, this manga is a perfect example of wasted potential. The art is amazing, and the setting was really good, but then it just went nowhere. The issues with Haruka's family never got solved, the tease about her sister was pushed under the rug, and then Haruka herself was just pushed into the background while Mizuki got all the focus and development. I doubt that was the author's intention, but by the end, I was rooting for Mizuki and Saeki to get together because they had such a more compelling relationship, but then it just ended with Saeki and Haruka together just because.
Ah well, at least the expressions were on point and I got a good laugh out of it.