Oshigiri Sakura

Sakura Oshigiri is currently a part of the Underground with Omejima Nanami and Akafuda Chihiro, and is Zakuro's twin sister. She can be seen as kind and caring towards both the members of the Underground and Kaikoku.

Appearance
Sakura's appearance is very similar to Zakuro, except more feminine. She wears a sleeveless black top with an open, white hoodie with elbow-length sleeves. Light brown, cuffed pants which go down to her ankle, a black belt and dark brown laced work boots. Sometimes, she would wear protective gear, such as a headlamp, when exploring or searching for parts.

Personality
Sakura is portrayed as kind, caring and considerate towards others as shown when she took care of Kaikoku after he was knocked out. She's very calm and know what do in dangerous situations like when Kaikoku was attacked by a ningyo (literally meaning fish-person) when collecting parts with Sakura. She's also adventurous because she ventures out on her own for parts, which, as a result, she get scolded often by Nanami. Sakura clearly cares for her brother as she feels guilty for accidentally hurting him and she purposely tells Kaikoku to not tell him about her because he is bad at hiding his emotions.

History
When she was very young, she accidentally hurt her brother with scissors as she tried to cut his hair. Sakura started playing the beta version of 'Naka no Hito - Genome ' in 9th grade and was kidnapped to the island just before completing the game. She was part of the 11th District with Akafuda Chihiro until she was disqualified into the White Room. Chihiro purposely broke the rules to accompany her. After fining the secret passage and meeting Nanami, the three stayed in the Underground until Kaikoku came across the passage. This was when she found out her brother was also in the game.

Season 1 Episode 9: Heaven White and Hell Black
In this episode, Sakura makes her debut when she is shown to be caring for Kaikoku who was knock out due to Nanami's handmade stun gun. As Kaikoku wakes up, he sees the similarities between Zakuro and this girl (who was unknown to him at the time), grabs her hands and identifies her as Sakura. Shocked, but calm, she confirms her identity and asks who Kaikoku was. A little later, Nanami walks into the room to explain his actions, introduce the members and welcomes Kaikoku to the Underground. A while later, Chihiro walks into the room where Kaikoku and Nanami were discussing about the avenues to report that Sakura has gone missing. It is later found that Nanami asked Kaikoku to search for Sakura near the path to the reservoir. As Kaikoku finds Sakura, she is seen with a toolbox, disassembling something with a screwdriver. The two began talking about Kaikoku's change in appearance and Sakura's sudden 'disappearance', how she should correct it. They continue down a path to look for radio parts, which was later confirmed to be for Nanami who was in need of them. On the way, Sakura asks Kaikoku about her brother Zakuro and whether he was alright. While retrieving the parts, Sakura tells Kaikoku that she will give the parts to Nanami as a present.

To return back to the 'base', the two needed to pass through a waterway. Sakura talks about the ningyo (fish-person) which was thought to appear in this waterway. As the episode ended, the water rippled near where the two were standing.

Season 1 Episode 10: Hold On and Let Go
This episode starts by revealing that the ripple was caused by a kingyo (goldfish). As Sakura heads closer towards the 'base', Kaikoku's feet seemed to be tangled up within something and he was pulled underneath the water. He was submerged up to the point where he couldn't breathe, but Sakura injures the ningyo freeing Kaikoku, who was half unconscious and brought him to the surface. As the ningyo was about to attack them from above, Nanami appears injuring and scaring the ningyo. However, the ningyo  still continues to follow them and Nanami starts to tease Chihiro about it.

As the four were walking back, Nanami talks briefly about his partner Niki who helped build the secret tunnel out of the White Room. He then changes the topic and starts scolding Sakura for venturing out on her own and dragging Kaikoku into it. She didn't have the courage to say that she was collecting parts for Nanami, but Kaikoku encouraged her to tell him. Nanami was thankful for her. After returning, Sakura found out that Kaikoku has caught a fever. Despite that, the two talked about the blueprints which Nanami gave to him, his partner and about Sakura going with Kaikoku to meet Zakuro, her brother. Chihiro barged in the room to say that there is a big problem (there are people in the white room looking for Kaikoku). After arriving back in the White Room, Sakura heard Zakuro talking to Kaikoku and began crying softly. Before Kaikoku left, Sakura shook hands with him as a message for, and told him not to tell Zakuroabout her. On their way back to their rooms, on the stairwell, Kaikoku shook Zakuro's hand (like what he and Sakura did) and said 'I'm so glad you're okay' (a message from Sakura to Zakuro), but Zakuro didn't get the message.