Sakurako Sakurakouji

Sakurako Sakurakouji is one of the Four Founders of Eden and is Sakura's real mother. She is known as "The Amazon".

Background
Sakurako is one of the Four Founders of Eden, alongside Heike and Code:Emperor. She carries a long katana similar to Rei's. Her katana was revealed to eliminate both Rare Kind power and special power in recent chapters. She really loves her daughter. Her personality is somewhat of a mystery at this point, as are her intentions. The doll who restored the Emperor, Kurako, belonged to her.

There is a possibility that she also created Inoichi, another doll who is supposed to protect both Sakura and the Pandora's Box. All the mechanical dolls share the same emotions as Sakurako, allowing her to feel their emotions too.

She is Shibuya's ex-wife, as seen in chapter 126, when Yukihina almost told Sakura that Shibuya was Sakurako's ex-husband.

Shibuya
At one point, they were husband and wife, and had a daughter. They separated for unknown reasons.

Heike notes that Shibuya feared her.

Sakura
There are some hints in the latest chapters, especially in Ch. 179, that her parents are Shibuya and Sakurako.