Kosako Shunichi

Kosako Shunichi (小佐古俊一) is an anime-original character introduced in the Toaru Kagaku no Railgun S anime series. A bespectacled student of an unspecified institution in Academy City, he is a member of STUDY and acts as Aritomi Haruki's second-in-command. It is a group that desires to show their power in their esper-obsessed city and plays an antagonistc role in the Silent Party Arc.

Appearance
He is a tall and slender bespectacled male having light brown hair. The brown hair is combed and parts at the left side of his head. The fringes are styled to complement this and are combed away from each other. He wears rectangular glasses, and is often seen wearing a lab coat over his uniform of sorts, which consists of a buttoned-up collared shirt and pants, both blue-green in color. Kosaka Shunichi's physique seems appropriate to his interests — slim and lacking any muscle — that may suggest a lack of exposure to strenuous physical activity.

Personality
Like the other members of STUDY, Shunichi displays a strong desire to show Academy City their power. In doing so, Shunichi is just as willing to sacrifice Febrie, if it means furthering their goal just, as any other member of STUDY, with the exception of the newcomer Nunotaba Shinobu.

Background
A specialist in the field of development biology, Shunichi entered the Academy City Research Exhibition Assembly like Aritomi Haruki. He later becomes disillusioned by the City's focus on esper powers, and joins up with Haruki for the Chemicaloid Project to show the city a different method in creating espers. He later joins up with the STUDY Corporation and continued to the project on their own without the support of other underground organizations.

Shunichi temporarily assumes command as Haruki steps out of the headquarters, showing up in one of the venues of the Academy Assembly to personally double-check one of his deliveries sent to the venue and to look for their target Febrie. Although he has located Febrie, Aritomi was unable to eliminate her using security robots under his control. However, the involvement of the rank-third Level 5 Misaka Mikoto in Febrie's rescue has sparked Aritomi's interest in having her as a test subject, which STUDY unanimously agrees to.

Silent Party Arc
Like most of the members of STUDY, Shunichi often stays inside the main headquarters, contributing to the smooth progress of their leader Aritomi Haruki's plans. He is the most vocal of Haruki's subordinates, and acts as his second-in-command.

He is not present in STUDY's first appearance, but is the one who informs him that Febrie has escaped. He later joins up with the rest of the group, discussing their success in gathering data about the ranked fourth Level 5. Despite Febrie's escape they decide to proceed with the next stage of their plan, and casts a unanimous vote.

Shunichi temporarily becomes the leader of STUDY as Aritomi steps out of the headquarters, showing up in one of the venues of the Academy Assembly to personally double-check one of his deliveries sent to the venue and to look for their target Febrie. Although he has located Febrie, Aritomi was unable to eliminate her using security robots under his control. However, the involvement of the rank-third Level 5 Misaka Mikoto in Febrie's rescue has sparked Aritomi's interest in having her as a test subject, which STUDY unanimously agrees to.

Haruki and Shunichi later had a Powered Suit kept in an old warehouse while they try and lure Mikoto and her friends (Febrie included) into an ambush by manipulating the routes she was taking and interfering with cellphone signals to stop them from making any calls. During this time, they monitor the events while inside a black van, watching as Mikoto battles the Powered Suit (which was later discovered as unmanned and lacking electrical parts by Anti-Skill). They later made their escape when Kongou Mitsuko unexpectedly appears and defeats the Powered Suit they had prepared. Despite the interruption of their short experiment, Haruki was able to conclude that their experimentation on Mugino Shizuri may also work on Mikoto as well.

He appears before STUDY again, discussing on how they must be wary as the Assembly draws close despite silencing Anti-Skill after Haruki brings up the topic. Madarame Kenji then states his worry in leaving Febrie alone, to which Sakurai Jun tells him that they already voted on that topic yesterday, to which Kenji replies that he is just checking since he doesn't want anything ruining their presentation. Sekimura Hirotada then mentions that Febrie will be dead before the exhibition, and that they need not worry as she is merely back-up anyway. Jun then says that the exhibition is drawing close and that they should prioritize in tuning Janie. Haruki then asks if the preparations are going well, to which Hirotada confirms and asks Shinobu, who says that she will do her best for their presentation.

Once again with the others, he notifies the others that there has been a trespassing at the first lab ( wanting revenge). Hirotada asks who the intruders are to which Shunichi cannot determine. Haruki mentions that the first laboratory is a bait with light security and that it will not be unusual if someone took the bait. Jun then adds that even if the intruders found the land, it doesn't matter anymore. Shunichi asks if there are sensitive data, to which he is informed that there is none as it has been move, other than the data regarding the poison neutralizer, the same one that keeps Febrie alives. He later witnesses Shinobu telling them that she will check the first lab to make sure. Hirotada mentions that she will be treated as an intruder as well if she goes there, to which she says she has no intention in getting into danger when the their plan is in the final phases, it's just that she just want to confirm if there won't be a single uncertain variable in their equation.

After they discover Shinobu's betrayal and capture Misaka Mikoto, he is in a van with Haruki and Kenji when the latter infoms them that there has been an intruder in the office building where they are keeping the two girls, and that the Security robots have been taken out. Shunichi is with Haruki and Hirotada after Mikoto escapes the place, and there they restrain Shinobu with handcuffs. Haruki is impressed by Mikoto's power and asks why Shinobu didn't run as well. Here, Shinobu says that since she was sold into an underground organization, if she escapes then every underground organization would be after her, something that is equal to death in Academy City. Haruki is elated by Shinobu's complacency and tells her that if she did run away then they would've forced Janie to do their bidding. Their, Haruki tells her that she is in the darkness now and that she should remind herself that as she keeps working for them.

STUDY later moves to their base of operations for the Silent Party alongside Shinobu. The following day, at the day of the Academy City Research Exhibition Assembly, STUDY initiates the Silent Party plan, which involves a four-way offensive against the four facilities that would host the Academic Research Exhibition Assembly. Before the break of dawn, they make one final vote to carry out the plan, to which everyone other than Shinobu agrees to.

During the day of the Silent Party, he joins Madarame Kenji in piloting their own mechas, apparently as a back-up when their main force of 20,000 and more Powered Suits are hindered in their attack on the Assembly venue. He and Kenji are later ordered by Haruki to attack the Judgment members that have come to oppose their rebellion. They are later struck down by the arrival of Yomikawa Aiho driving the Ekaterina II S. After coming to, he is ultimately forced to engage the transforming mecha piloted by two middle school girls, Saten Ruiko and Uiharu Kazari, on his own, but his mechanical unit is swiftly defeated. Shunichi later escapes the ruins of his machine and falls unconscious.

It is implied that he joined Aritomi and the other associates of STUDY as they were taken into custody for their crimes.

Abilities
He is a normal human, though he is at least skilled enough to operate a mecha on his own. However, this skill is not enough to defeat the much larger mecha piloted by Ruiko and Kazari, who just learned to pilot it the other night by memorizing its manual.