Ken Sudō

Ken Sudō is a student of class 1-D and a member of the Basketball Club.

Due to his poor academic ability, he is referred to as one of the 3 Idiots of D-Class. Regardless of this, his athletic ability is without a doubt one of the best among the school.

Appearance
Aside from his dyed red hair and an inappropriate hairstyle, he possesses an intimidating look, which makes it harder for others to get close to him.

His height of 183 cm combined with his sturdy, muscular physique easily leaves an impression of a competent athlete on others. His clothing style also portrays his wild and aggressive personality, as he lets loose of his upper shirt's buttons.

Personality
Ken puts very little efforts into his studies, which grants him the nickname with two other classmates the "3 Idiots of D-Class". He is always seen to sleep in class, and also once refused to join Suzune Horikita's study group for the sake of his grade.

He is known for having a hot headed temper, being quick to get angry when people do what he deems pointless or if someone insults him, showing how easily provoked he can be. When others attempt to help by stopping him, he exclaims how he doesn't need their help and gets angry as the person who taunts him walks away. Despite his eagerness for a fight, he is shown to get scared when he is overpowered as shown in his confrontation with Kakeru Ryūen.

Ken enjoys basketball and wants to go pro, and is very attached to this dream as he was worried when Suzune mentioned he might not be able to play if he were to be expelled from the school.

During the cruise in Episode 8, he quickly asked Kiyotaka Ayanokōji about Suzune Horikita's first name and after being told he got excited. He blushed while saying her name repeatedly, showing he may have developed romantic feelings for her, despite their previous hostile interactions.

Plot
He is first seen criticizing Yōsuke Hirata for proposing that the class introduce themselves, calling it childish. After he and the class were told about points, Sudō was one of the most excited and during the month he used his points for trivial things while often hanging out with Kanji Ike and Haruki Yamauchi. He nearly got into a fight with students of C-Class but they decided to leave while mocking him.

Days later, he was approached by Kiyotaka to join Suzune's study group but angrily refused, while afterwards Suzune herself met with him and made him think about his athletic career and how it could be at stake if he were to be expelled, persuading him to study. However, he left after Suzune insulted the idiots and is joined by Ike and Yamauchi. He is next seen getting into a confrontation with C-Class, being grabbed by two students of the class and intimidated by Kakeru. He broke free and tried attacking Kakeru but the fight was broken up by Honami Ichinose and C-Class walks off, and when Ken tried to stop them, he was stopped by Kiyotaka. In a huff, he refused to rejoin the study group and went to basketball practice while his thoughts were filled with doubt of becoming a possible failure.

Afterwards, he is given the old test scores obtained by Kikyō Kushida and is relieved to hear that there was a chance to pass the test.

While the whole class passed the test, Ken was the only one who didn't get a passing grade, being one point away due to the class average. He was told by Chabashira that he would be expelled immediately, much to his dismay. Unbeknownst to him, Kiyotaka and Suzune came to his aid band sacrificed 50,000 points so that he wouldn't get expelled. Later on, a celebratory party was thrown at Kiyotaka's room where Ken and some other students from D-Class attended with him, relieved that he didn't fail. When Kikyō talks to Kiyotaka and hinted that he helped Ken out, the latter and the others stopped their activities and looked to see if this was true but Kiyotaka passed the credit to Suzune. A startled Suzune barely explained to a curious Ken that she did it for her own benefit.

Sometime later, Ken got into a fight with Daichi Ishizaki and other students of C-Class on the stairwell. He overpowered them which caused them to file a complaint against him, which again, could possibly lead to his expulsion. As a consequence, his class does not receive points, and Ken ended up being berated for his confrontation by D-Class, still insisting his innocence. When Kushida formed a group to prove his innocence, they met in Kiyotaka's room after their search for witnesses proved fruitless, before Suzune arrived and proclaimed that she found one. Suzune told them that Airi Sakura witnessed everything but did not want to come forward with her knowledge, much to Ken's annoyance.

At the hearing, he was accompanied by Kiyotaka and Suzune as well as Sae Chabashira. Things didn't go his way at first until Suzune (with Kiyotaka's help) spoke and delivered a speech which implied that the fight was a set-up. She further proved it by asking all three boys of C-Class why they were all present at the stairwell and why, with all their strength, they got injured while Ken remained unharmed. Ken was surprised to see that Sakura decided to come forth. He is further shocked when she provided proof of her presence with a picture of herself and a glimpse of the fight in the background. This was pushed aside as a minor detail as it didn't prove who started the fight, but rather that she witnessed it, causing Kazuma Sakagami to propose a compromise. He suggested a three week suspension for Ken while a two week sentence for the students in C-Class, but Suzune refused it. She voiced her opinion of Ken where she criticized him, which riled him up at first, but she followed up stating that he was not at fault for this incident, much to his shock. Ken watched on as Suzune demanded the dismissal of the accusations towards him while also becoming amazed by her speech. He got into an argument with C-Class about his innocence but the argument is halted by Manabu Horikita who said he will give his verdict the next day.

A day later, C-Class withdrew their complaint against Ken, much to his joy. At the courtyard, he found and informed Kiyotaka of the news (not knowing that he was to blame for this act). Kiyotaka congratulated him on this and when the relieved Ken wondered if Suzune did something to help him, Kiyotaka again gave her the credit. After the brief celebration, Ken called Suzune amazing for her actions before leaving for practice as Kiyotaka looked on.

On summer break, the Idiots of D-Class, Hideo Sotomura and Kiyotaka Ayanokōji planned to peep on the girls, inviting them to a day at the pool. After some unexpected events took place, Ike ended up being trapped in the women's locker room and a long line of people from other classes form wanting to get in caused the plan to force Ken to distract them. Ken is met with a problem when the student council President arrived demanding he move out of the way. Luckily, Sotomura had signalled Kiyotaka and he persuaded Suzune to distract everyone long enough for Ike to escape unnoticed. While the event took place, Suzune stole the memory cards for the peeping incident. Though the plan failed, Ken enjoyed his time at pool with his friends and classmates.

During the cruise, he quickly asked Kiyotaka over Suzune's first name and after learning it, blushed while saying her name repeatedly before leaving with the group. While getting lunch at a fancy area on the cruise, they were insulted by Yahiko Totsuka who berated them as trash, causing Ken to grab him but it was stopped by Kōhei Katsuragi.

During the special exam on the deserted island, Rokusuke Kōenji had ditched the exam, causing the class to lose 30 S-Points. Ken, like the rest of the class, was angered by this selfish act, cursing him out loud. This is followed up after D-Class had won the survival test, confronting Rokusuke about his decision and becoming worked up after he is met with an egotistical opinion from Rokusuke.

Trivia

 * In the light novel, Ken Sudō and Kiyotaka Ayanōkoji are actually friends.
 * The anime has not fully developed their friendship yet.
 * As D-Class is for people with defective traits, Sudō has a hot headed temper and low intelligence.
 * He has been at risk of expulsion twice in the series for two separate reasons that deal with a personality flaw of his. In both those times, he was saved by Kiyotaka Ayanokōji and Suzune Horikita.
 * In Episode 3, his inability to study causes him to be the only student to fail but he is saved by Kiyotaka and Suzune sacrificing their points which caused the teacher to change the decision.
 * In Episode 5, his quick temper and eagerness to fight causes him to be accused of attacking and injuring three students of C-Class. At his hearing, Kiyotaka and Suzune come to defend him to prove his innocence in the terrible incident. In Episode 6, he was cleared of the incident due to C-Class withdrew their complaint against him after they realized they were recorded by a surveillance camera.