Haruka Mamoru is a character on Tsuki's ship. Since Tsuki is gone, she is responsible for maintenance and management. She does this via a tablet of her own design. She thinks Saltimore is pretty neat and currently resides there.
Haruka was a young girl from a yet to be revealed location. When she was very young, only 2 or 3 years old, she was kidnapped by Delta Z and forced to murder her parents. From then on, she recieved training on how to make and operate a robot designed for murder, how to stab and shoot people. Her name and identity under Delta Z was Monaka. She proved herself as a valuable asset with a knack for programming and logical mindedness. She did her best, but got punished for underachievement nonetheless. She was forced to go through painful tortures (including murdering her friends) when she failed to meet deadlines or kill quotas. Among programming and acting as a remote soldier, she would also be used as an assassin due to children being unsuspicious, her way of killing, and being able to think quickly about how to get out of a pinch. When she was around 9-12 years old, she became aware of Tsuki's ship, and started hatching an escape plan.
Haruka first got in contact with the ship using Tsuki as an alias, after escaping the facility. She eventually got on the ship using sleeping gas and a gas mask (which notably did not affect Natsumi). She hijacked Delta Z later, where she learned her branch was the last branch to not die out or join the Collective. Following this, she raided her base and killed the last leaders of Delta Z, but during this was captured and tortured to the point of attempting suicide. After this was over, she designed and released the Electronic Guidebook for use by ship members, and later discovered her given name (but hid that she had forgotten). The crew next went to Sillyland where they spent a lot of time. Haruka got a twitter account (@MonakaDev) and lazed around for months, feeling bored. When Cherryapple Picklechips came, Haruka jumped at the chance to do something new, and currently is looking at the mechanics of Saltimore, because she would like to move there.