|School||Hiiragi Academy's "Ichou" Branch Campus|
|Manga Debut||Chapter 34|
|Anime Debut||episode 9|
|Japanese Voice Actor||Aki Toyosaki|
|English Voice Actor||Tia Ballard|
Despite being a guy, he resembled his avatar very much, looking like a real girl to those who don't know his identity. During middle school, he tried to walk out of his house wearing girly clothes, but ended up accidentally bumping into and hospitalizing a classmate who discovered his secret hobby and made fun of him. Ever since then he was not only afraid to leave his home, but also meet other people and question his gender/identity. In the end, Kagami was able to convince Koutarou to reveal his true identity to his classmates after a final match with First (Kagami's character) which ended in his victory. Koutarou has returned to school, and his classmates accepted him as what he really is. He was also given permission to wear a girl's uniform and was FORBIDDEN to wear the male uniform by Koyomi Hiiragi because he was too cute to be male.
Before his introduction, he was once in the same middle school as Shikishima Kiriko. Koutarou's online identity in the MMORPG 'Uroboros' is 'Luce', the ironclad sister/iron bulwark nun, who is female. Koutarou's only motive for signing up for Ouboros was because he wanted to create a cute avatar and buy cute items, so he only played offline. That was until 'First' came up to Koutarou and asked him to join his party, so that Koutarou will be able to complete his collection of cute items.
Years later when Kagami became a teacher, he decided to make his students sign up for Uroboros so that they have enough members to attend an event. Upon being one member short, Kagami went to Araki Koutarou's house to get the last member for the event requirements and make him attend school. When he entered his room, he found out Luce was actually a Araki Koutarou, a crossdresser, who was really worried about being judged. Still being one member short, he asked Luce to continue leading his class while he went to find the last member, surprising Araki Koutarou.
Before the event, he convinced Momozono Makina to sign up and attend the event to fill the last required position, on grounds that she would meet the truant. At the event, 'Luce' went afk after logging in, thinking it best he didn't interact with them. Kagami went to his house, and caught him running away, before convincing him to stay and finish the event. Some time after the event, 'Luce' confessed to Nanami Seijuurou that he was Araki Koutarou. To Koutarou's suprise, Nanami was fine with it. Then Kisaki approached Koutarou to talk about Nanami, and take him to school. But before that, went shopping to get him a cute outfit, and met up with Momozono, who invited both of them to her house. Koutarou was shocked at the hospitality of his classmates, and thankful.
He then had a battle with 'First', on pretences he would reveal her secret, but at the end of it, he told them himself, and was surprised at the acceptance of his classmates. After that, he went to school dressed as someone who he was, in the female uniform, worried about acceptance. President Hiiragi, known as 'Options', came to see his return to school, and upon seeing him, prohibited him from wearing the boys uniform, including having him taking swimming classes in a girl's swimsuit too. Araki attended class regularly after that.
Afterwards, he names Kanan as his older sister due to her talent of creating cute things in Uroboros, and is chosen as one of the five branch students to follow Junichirou to the main campus to partake in the SS group war.
As a member of Silver Core, he participates in the soccer match against team Titan, but is replaced by Junichirou part way through due to injury. Afterwards, he participates in the seduction match against The Legends; struggling at first, but starts to seduce girls of his own after realizing that Junichirou had turned him into the internet mascot, "Arakki."
34, 35, 36, 37, 38, 39, 40, 45, 46, 47*, 48, 49, 50, 51, 52, 53, 54, 57, 62*, 65, 66, 68, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98*, 100**, 104