Reiko Tamura

Reiko Tamura (田村 玲子, Tamura Reiko), originally known as Ryouko Tamiya (田宮 良子, Tamiya Ryōko), is a parasite and one of Shinichi Izumi's high school teachers. Although she is usually emotionless like other parasites, after giving birth she became increasingly maternal to the point that she gave her life to save her son. She is a major character with many of her actions affecting the plot.

As Ryoko Tamiya
In her first appearance, she had shoulder-length light purple hair that has hair strands swept to the right side, sharp brown eyes with bags underneath them, she had an average height and a slim build.

Both students and other teachers such as Sasaki were interested in her good looks.

In the manga, she had purple-tinted brown hair while posing as Ryoko and she appeared to wear heavier make-up and jewelry before she discarded the persona. She also had an intermediate appearance with loose wavy hair while pregnant.

As Reiko Tamura
With her second appearance, her body type remained the same, but her skin became fairer, she now had upper-back length black hair that has bangs swept to the left side and a more pointed face. Her expression changed to one that was calmer and relaxed.

She was often seen wearing formal attire and lipstick.

Personality
Reiko was a highly intelligent parasite with scientific inclinations and a drive to discover the biology, origin, and purpose of parasites. She often studied the human psyche alongside her examination of her own species. Although initially just as cruel and unfamiliar to human psychology as her fellow parasites were, she slowly grows to understand human emotions and reactions.

She is more logical and reasonable than many other Parasites and allows Shinichi Izumi to live unmolested largely because she finds him an interesting anomaly worthy of study, despite other parasites instinctively thinking him a threat. She displays curiosity at Gotou's progress and finds the pursuit of information more important than staying safe. Even when threatened by her own species, she is more interested in the fact that parasites are developing further and further from the blank slates they began as.

She is quite manipulative, capable of using her studies on human and parasite psychology to predict reactions and steer individuals towards her own aims. She is also aware of her own higher capability over most other parasites, as seen when she mocks Kusano and his teammates for believing they could beat her in a 3-versus-1 battle.

Initially, Reiko is very callous towards her child, planning to either experiment on it or eat it. She holds it poorly, and has it "trained" to stop crying when she commands. After giving birth and raising her child, she began developing and showing human emotions, such as laughter and love towards her son. She is eventually surprised by her own unconscious attachment to her child. Despite her initial lack of emotion, she also seems to gain a mischievous streak, laughing at Shirou Kuramori when he became flustered and tipped over a table as well as when causing a crowd of humans to panic.

She sacrificed her own body to keep her son safe as the police shot a barrage of bullets at her. Before succumbing from her wounds, she revealed that she truly believed humans and parasites to be the same and that she enjoyed the time she had spent living as a "human".

Plot
Ryoko starts off as a substitute teacher in Satomi Murano's homeroom and math class, having managed to keep her original host's identity free of suspicion. She meets with Shinichi Izumi and displays no hostility towards him, instead convincing Migi to meet with her in the Herald Coffee Shop for the purpose of sharing information. In secret, she brings along A, who immediately identifies Shinichi and Migi as a threat. Although A and Migi posture menacingly at one another, Ryoko reins them in and speaks with Shinichi, revealing that she is pregnant with a human child. She concludes that parasites have no means of reproducing themselves. A displays no interest in the conversation and leaves midway through, while Ryoko threatens to kill all of a class if Shinichi causes her to be revealed.

Soon after, A is revealed to still consider the human-parasite duo a threat, and invades the school in broad daylight in an attempt to kill Shinichi. She quietly calls him a fool and leaves the classroom, right before an announcement is made for the students to evacuate.

After A's human host body is damaged by Shinichi's actions he tries to find Ryoko in hopes to transfer to her host. He tracks her to a room where she turns out to have set explosives, and she jumps out the window as the room explodes behind her with A still inside.

Later, Ryoko is invited to a staff conference and, because she is a pregnant single mother with no identity for the father, berated over the damage this would do to the school's reputation. Surprised that it is the pregnancy causing problems for her human life (likely having expected for Shinichi or a murder to cast suspicion on her instead), she then decides to quit being Ryoko Tamiya and leaves.

When Ryoko's mother learns from the school that her daughter was fired, she headed straight to Ryoko's home to see if what was wrong. Upon meeting her, she then realizes something is very different about her from the daughter she knew. Deciding that this can no longer be her daughter, she attempts to call the police. Ryoko morphs and beheads her before she can.

During her pregnancy, Ryoko changes her name to Reiko Tamura and meets up with Hideo Shimada. She convinces him to keep an eye on Shinichi as Hideo's host body is teenaged and capable of blending in, and the two parasites begin experimenting with supplementing their diet with normal human food. She also occasionally meets up with Takeshi Hirokawa.

Some time after Hideo's death, she eventually gives birth and returns to the parasite meetings headed by Hirokawa, leaving her child to a human babysitter. After convincing the other parasites to allow her to take responsibility and research Shinichi instead of killing him, she hires Shirou Kuramori to spy on him to see if anything changed.

Some time after Kana's death, he ends up attacked by Migi. He and Shinichi, along with Mamoru Uda and Jaw, eventually turn the tables on Kuramori and convince him to spy on Reiko instead. When he goes to meet her, she dismisses his account of Migi's attack and suspicions as mad ravings and tells him that she's done with him. Flustered, he attempts to stop her from leaving and falls, causing her to unconsciously laugh on the way home.

She eventually catches him in the act of tailing her, prompting him to send Abe instead, who watches her meet Miki and is then caught and killed by him. Kuramori goes with Shinichi to the parasite safehouse, where they catch another parasite about to eat someone.

Once Shinichi and Migi manage to kill him, the group of parasites change their minds about letting Shinichi live and overrule Reiko. Because of her defending Shinichi and later warning that Kuramori is out for revenge after the murders of his wife and child, Kusano decides she is a threat and conspires with two others offscreen to kill her. The evening they meet, she ends up killing all three of them with no injury, but discovers her child was kidnapped by none other than Kuramori while she was fighting them. In the interval between this discovery and the meeting time he sets, she visits Shinichi's house while the occupants are away and goes through Shinichi's baby pictures. She manages to set up a meeting with Shinichi shortly after Kuramori's meeting time, crossing Satomi's path on the way out.

Reiko meets with Kuramori one last time and kills him after he threatens to throw her child off a balcony, both of them expressing surprise that she genuinely had maternal feelings. In a park nearby after she meets with Shinichi and informs him that Gotou's capability is far beyond his, as well as hinting towards Hirokawa's true nature, the police interrupt their meeting and proceeds to shoot her.Unwilling to allow her child to be harmed, she forms a shield over it at the expense of her own protection and walks toward Shinichi. He begins to back away, and in an effort to gain his trust, she changes her face to that of his mother. He stops long enough for her to hand him the infant, give a small speech and later dies.

Her death causes Shinichi to start crying after a long time of inability to cry. The baby survives because of her decision not to fight back against the police and is eventually put up for adoption.

Abilities & Powers
Being a parasite, Reiko can shapeshift from the head up and and harden her cells for offensive or defensive purposes, as well as detect other parasite signals and automatically emit her own. She can also maximize the host body's physical potential and disregard pain. Like other parasites, she can mimic another person's face, as seen in Episode 18 where she mimics Nobuko Izumi in order to gain Shinichi Izumi's trust. Her high intelligence allowed her to make use of unorthodox tactics when engaging enemies. She is one of the few parasites shown using tentacles to propel her around instead of walking or running, as well as the only singular parasite with more than one attack pattern. When targeted by three of her own kind, she tricked them into believing she had gone insane when she split her parasite in half.

She was able to lure away Kusano and simultaneously prevent him from killing her host body by running in front of witnesses, kill Maesawa while separated by allowing the detached portion of herself to burrow and destroy him from within and then trick Kusano into killing Hikawa by burrowing into her and forcing her to attempt to kill Kusano. He kills her, allowing Reiko to sneak up on him and kill him when he unintentionally jams his ability to sense other parasites when he hacks Hikawa up.

In the Live Action film, she is able to split her parasite body in three, using them to pierce the heart of three of her own kind from behind, killing them without letting them notice. She can also extend her hair and wrap them around her son to protect him from the police's gun shots.

In addition, her intelligence and interest in the human mind allowed her to more effectively blend into society. She managed to keep her original host's identity before she decided to discard it, impressing Migi in the process.

Weaknesses
Like all parasites, Reiko requires a host body with functioning organs to survive, and would die if she were separated from the body or it was destroyed. Fire can cause her parasite cells to "freak out", making her lose control. She is also susceptible to poisons or caustic chemicals, which would either kill parasite cells on contact or make her host body fail.

When she was still posing as Ryoko, she used more of her host body's strength than it could take, accidentally dislocating a shoulder when she threw a man out of a train.

Although her intelligence and curiosity allowed her an advantage over her opponent parasites, it also caused several of them to target her in the first place, believing her to be a danger.

Original

 * The original name Ryōko means "good, virtuous, respectable" (良) (ryō) and "child" (子) (ko).
 * The original surname Tamiya means "field, rice paddy" (田) (ta) and "temple, shrine, palace" (宮) (miya).

New/Current

 * The new name Reiko means "the tinkling of jade" (玲) (rei) and "child" (子) (ko).
 * The new surname Tamura means "field, rice paddy" (田) (ta) and "town, village" (村) (mura).

Trivia

 * In the Tokyopop westernized release, Reiko is renamed Tamara Rockford.
 * Reiko appears in the Parasyte Reversi spinoff.
 * She also appears in the short story Teach Me! Ryoko Tamiya-sensei! and is shown in flashbacks in Through Yura's Gate, both from Neo Parasyte M.