Story - 4

Harem-romcom that lackluster in romance and comedy side, while somehow put forward mystery (without satisfying conclusion) side more.
Have a lot fun & fluffy arcs but become a huge pile of mess when author tried to tied it all together.
Too many "Red Herring" (thought i read a fishing magazine).
A huge portion (give or take 90%) of the stories are irrelevant to the ending outcome.

Art - 8

Lovely character design (hard to not like every quints).
Enough emotion to convey character feeling.
Detail is there.
All in all, it's good (nothing to complain, nothing blew my mind either).

Character - 6

Main cast have distinctive personality (which is good).
Character development is a mess for every main cast, instead making "winner" girl looks good, author just straight up making other girls look worse.
By the end of the manga, never though they're 5 sisters, they just 5 close friends that live together.

Enjoyment - 6

really enjoyed reading it at first half then it start deteriorating from there, and free falling for the last 1/4.
With how the ending conclude, the amount of red herring and irrelevant stories, reread the whole manga just make my enjoyment worsen.

Overall - 6

one of the running themes is "when you love someone enough, you can differentiate her from other (quints)", by the end of the manga, Fuutarou can differentiate every quints easily, how am I supposed to feel about that?

"writing a mystery is easy, make a good (or somewhat okay-ish) conclusion is the hard part".