|Birthday||December 5, 1991|
|School||Kaimei High School (chapters 1-205)|
National Tokyo University (chapters 205-present)
3-A (chapters 1-205)
|Likes||Afternoon naps, shogi|
Saaya Agata (younger sister)
|Manga Debut||Chapter 10|
|Anime Debut||Episode 1|
Sōjirō is known to be quite handsome (depicted briefly by Himeko and strongly admired by Yabasawa), he puts up a charming smile which accompanies his idle ways. He is tall with an athletic build. His dark hair can be considered to be messy; it perks upwardly forward with strands falling on his forehead (similar to faux hairstyle).
Although Sōjirō is generally come across as laid-back and lazy, he is actually very shrewd and cunning. However, a few people seem to know about this side of him. Sōjirō has a bit of a devious side as demonstrated in these two occasions. During the Gachinko Vivage Battle, he makes Bossun bet his club's fate just to make things interesting. The second occasion is where he and his friends along with the Sket Dan purposely push Sasuke and Bossun into spending time together. With an IQ of 160, he is intelligent enough to outwit Bossun and solve difficult brain teasers. He seems to possess a high level of charisma, as evidenced by Tsubaki and Kikuno Asahina's loyalty toward him. Despite his keen observation skills and ability to plan ahead, his ability to think rationally becomes compromised when Saaya Agata (Sōjirō's younger sister) is involved. He is the epitome of an overprotective brother, even going so far as to try and help Saaya's love life (with often disastrous results).
Major Story Points
Sōjirō and the rest student council had to clean the principal's bust after he marked it with a permanent marker. Through their fail attempts, they end up destroying the bust.
Shinba Michiru's Elegant Cooking
After Shinba informs his student council friends that he is doing cooking segment, Sōjirō gets upset when Shinba picks Mimori and Tsubaki as his assistants. Eventually, Mimori has everyone drew lots. Despite that Sōjirō and Daisy got on Shinba's show, Sōjirō loses his enthusiasm while Daisy is not in the mood. When Sōjirō uses cooking saki, Shinba gets drunk and wreaks havoc around the set. In an anime exclusive scene, Sōjirō recalls how Shinba got drunk with bonbons during Christmas.
VS Student Council! Battle Q
While Sōjirō is preoccupied with a meeting, Enigman and his team force Sōjirō's student council to play a game. If Sōjirō's student council loses, Enigman will release a photo of them breaking the principal's bust. After the student council fail to answer the riddles, Sōjirō arrives and solves every riddle just by looking at the answers of his teammates.
The last day of the president
During the president Agata's last day, Shinba, Bossun, and the rest of the student council did a surprise game. After Sōjirō believe Saaya was kidnapped, he solves the riddles and sees Shinba and the others' message.
The Sister Who is Worried About Her Brother Who is Worried About His Sister Worries Her Friends
After Sōjirō fails his college entrance exams, Shinba, Saaya, and the Sket Dan formulate a plan to get Sōjirō focused on studying. When Sōjirō arrives at Kaimei High School, he spots Shinba and Saaya breaking up. Unbeknownst to him, Sōjirō is watching all four scenarios that was set up by Shinba. However, Sōjirō's original love diagram for Saaya becomes more complicated.
During Sasuke's farewell speech, Sōjirō yells to Sasuke to stop him from crying. Afterwards, it's Sōjirō's turn to give a final speech. Unlike Sasuke's speech, Sōjirō makes a quick improvisation in his speech when the mood has changed. He tells his classmates not to regret anything and move forward. Then, Sōjirō reveals his "mark" on the school, a wall decorated with foot prints of all the seniors. Later, Sōjirō and Shinba meet up with Sasuke's student council and the Sket Dan to exchange farewells. 
Sōjirō Agata is an intelligent man with an IQ of 160 who can solve difficult problems easily. This is best demonstrated when Sōjirō answers all of Enigman's problems just by using the cards that his Student Council members had answered wrong. Another example includes Sōjirō was forced to solve the riddles that Tsubaki, Bossun, and his Student Council had left when they pretended to kidnap Saaya.
Saaya Agata: He has a major sister complex, only to overreact when it comes to Saaya's well-being; he would usually lose all focus and astuteness if anything happens to her (such as who she harbors feelings toward or if she was kidnapped).
- He ranked 7th in the first character poll and 5th in the second.
- He is currently a graduate of Kaimei and is a freshman at Tokyo University.