If you liked
Seigi no Mikata
|
...then you might like
Fukuyadou Honpo
|
Both are josei manga that focus on sisters, but Fukuyadou Honpo has three sisters and has more romance while Seigi no Mikata has two sisters. The sisters' relationships with each other are more civil and friendly, and well... sisterly than Seigi no Mikata, where the elder sibling always bullies/spreads lies about her younger sister. But be warned, Seigi no Mikata was axed and did not get a satisfying conclusion like Fukuyadou Honpo did.
If you liked
Partner
|
...then you might like
Arisa
|
Both are manga about twins, but in Arisa, the title character goes into a coma after a suicide attempt while the other twin in Partner gets kidnapped by an evil organization to become a guinea pig for their experiments. As you can tell by reading the synopses and genre tags on MAL, they are both shoujo. However, Arisa lays more heavily on mystery while Partner is more of a sci-fi manga.
If you liked
Partner
|
...then you might like
Piece
|
TL;DR: Both are edgy shoujo manga with a sprinkle of romance. What starts the two manga is the disappearance/death of a character. In Partner, the missing person is the MC's sister while in Piece, it's the MC's classmate. The characters' pasts play a big role in Piece, but not much so in Partner. However, Piece's main character actively tries to solve the mystery behind the message her dead classmate left behind, while Partner is more of a sci-fi where an evil organization kidnaps people to become their guinea pigs. They both have romance, and in Piece it helps the characters develop and the mystery unfold. Meanwhile, in Partner, the romance is usually in the background in favor of the plot.