|Seidou High School|
|Bats: Right||Throws: Right|
|Nickname||Wolf Boy (狼小僧 Ōkami Kozō) (by Sawamura)|
|Age||15 (debut) |
|Place of birth||Kanagawa|
|Education||3rd Year Junior High |
1st Year High School
|Style||analytic and observing player|
|Skills||Soft touch catching; high baseball IQ, good Shoulder|
|Manga||Act I - Chapter 244|
|Anime||S2 - Episode 5|
|Voice Actor||Yuuma Uchida|
|“||He has a really soft touch when catching.||”|
— Miyuki about Okumura
Okumura has blond hair and pale, blue eyes (green in the anime); he is first seen wearing a red vest, black, long sleeved shirt and khaki pants.
Okumura has a quiet and very serious personality. He takes everything seriously and has a dislike for boisterous attitudes due to his middle school experience with his coach. Okumura also doesn't believe that it is possible for someone to both be serious while being able to truly enjoy baseball at the same time. He enrolled into Seidou to see if that is possible, along with how far would his abilities take him.
Although seemingly quiet most of the time, Koushuu can be very outspoken and often very critical about matters that he pays attention to, such as voicing his opinions on Seidou's pitchers, their respective performances or even a direct confrontation against Sawamura for being loud in the dining room.
Okumura watches Seidou's first round match against Teito High together with his close peer Seto Takuma, and by the end of the match, decides to go to Seidou High School.
He and Seto come to watch Seidou's finals match against Yakushi High. They are shown in the bathroom with Seto talking about Raichi and his skills as both a batter and a pitcher. They later run into fellow middle school students Yuuki and Akamatsu Shinji and they have a brief conversation about what High School they'll be enrolling to. While Seto doesn't recognize Akamatsu, Okumura does recognize the pitcher.
After the match, he is seen talking to Seto and Akamatsu.
Act II He doesn't make the cut to join the first string but still gets to join the first string at the bullpen during practice. He is seen catching for Kaneda.
One time during Seidou's lunch and most of the players are done eating, Okumura is left with Asada and Kuki. Sawamura calls out Asada inviting him to play catch. As Sawamura goes on talking to Asada, Okumura was annoyed by his blabbering. Okumura then frankly states his thoughts to Sawamura, even calling him an eyesore. Okumura stated he really hate Sawamura's boisterous attitudes and that he was disappointed with Sawamura. He later got called in to lecture by Miyuki for his action as the captain felt it could negatively affect Sawamura's performance and by extension, the team. After warning Okumura to reflect on his actions, Miyuki also suggests he should practice with Sawamura sometimes to fully understand what kind of person he is.
Although feeling irritated by Miyuki's lecture, Okumura later approaches Sawamura and offers to help him warm up after witnessing a frustrated Sawamura being left behind by Miyuki and Furuya. As he helps Sawamura warm up, he was visibly impressed with Sawamura's ability to constantly locate his pitch at the same spot. Miyuki noticed Okumura's eagerness to practice more with Sawamura so he told them to continue. Okumura for the first time demonstrating his catching ability as he was able to react and adjust to Sawamura's breaking fastballs, catching cleanly despite being his first experience with Sawamura's pitch. Although he could not catch Sawamura's No. 7, the Cutter Kai which would frustrates him every time he recalls the experience.
After Seidou lost to Ichidaisan in the SF of the Spring Tournament, Kataoka announced the reset for the jersey number and kick start the race to the Summer roster. Okumura and Seto are determined to get into the first string and for that they have to qualify for the second string first. He displayed more of his soft and serious side when he talked to Sawamura about his personal opinions on how he can become a pitcher everyone would recognize and then states he has to become a first string member first before he can catch for Sawamura. In his flash back, Okumura and Seto's coach only treated them nicely in the beginning but one day suddenly left them to coach a long time rival of their school. Feeling betrayed, Okumura rallied his teammates to win a game against his former coach to return him the favor. His middle school experience made Okumura hate people that only seem nice on the surface and that resulted in him disbelieving the existence of players that can be both serious while wholeheartedly enjoying baseball at the same time. It was also revealed that he enrolled into Seidou to find out whether his mentioned belief is true or not and how far would his ability take him.
Okumura, along with every other first year recruits, participated in the intrasquad game against the upperclassmen. He was subbed in by the 3rd inning where he forms a battery with Asada. After his demonstration in the intrasquad game, Okumura was chosen along with 3 others to join the 2nd string. However, despite achieving his laid out objective of making to 2nd string, he was dissatisfied with his promotion and would decline Sawamura's offers to catch for him stating he hasn't make it to 1st string yet because that was the promise he wants to fulfill before allowing himself to work with Sawamura; however, he would accept Furuya's request to practice in the bullpen shortly afterwards which frustrates Sawamura to no end.
Seto and Okumura attended the same middle school together and were also on the same team together. They came to watch Seido’s match against Teito in the Fall Tournament when choosing which high school to enter the following year and eventually decided to attend Seidou High. After enrolling at Seidou it's obvious that he sincerely cares about Okumura and often looks out for him, telling him that he doesn't have to push himself so hard.  But Okumura seems to be uncomfortable with his solicitude and made clear that Seto doesn't have to always wait for him.
As stated by Seto, Okumura held Sawamura in high regard prior to attending Seidou, who responds to Miyuki's aggressive game calling by throwing pitches that exceed expectations. But shortly after his enrollment an argument happens between these two as Koushuu was annoyed by Sawamura pestering to Asada. He said he felt disappointed with Sawamura but was later got called in and lectured by Miyuki for potentially affecting Sawamura's mentality and by extension, the team, as Sawamura is one of their key players. Miyuki suggested Okumura should try practicing with Sawamura to understand more about him. Taking interest in this, Okumura offered to help Sawamura warm up while the latter is waiting for Miyuki. After being impressed by Sawamura hitting the same location with every pitch during the warm up, Okumura seemed eager to continue practicing with Eijun which Miyuki noticed and allowed. He was visibly impressed with Eijun's Cutter Kai since he couldn't react to the pitch, missing it completely. After the incident, it seems Okumura has opened up to Sawamura and even offer the later his personal opinions on how he can become a pitcher recognized by everyone and that he like the serious expression Sawamura display as he practices. Although he still seems to dislike Sawamura's shouting on the mound and suggests he should change that because it makes the pitcher looks stupid. He later makes a promise that he'll catch for Sawamura as soon as he gets to the first string and start refusing Sawamura's practice offers and even Kataoka's order. After making the first string with Seto, Okumura comes to Sawamura and requests to practice with the latter immediately.
Player Statistics: Catcher
Miyuki notes Okumura possesses a soft touch when it comes to catching as he catch the pitches very cleanly, making a nice sound with his mitt. This helps ease up and instill confidence in the pitcher. It was said on multiple occasion that Okumura is a talented catcher and he is able to adjust to Sawamura's difficult moving pitches and hidden form and later Furuya's powerful and wild pitches on his first try when he catches for either pitcher. Okumura also demonstrated he has strong shoulders and solid defensive skills of a catcher, able to throw accurately right on top of a base plate for easy touch out.
Aside from his skills as a catcher, Okumura has also shown to employ a thinking-oriented play style by using the extensive processes of eliminations and predictions base on his knowledge and experience to reduce as much risk as possible and formulate a more advantageous situation for himself and his team. He can watch pitches with precision, feint a bunt or squeeze play to trouble the pitcher and draw Balls to work the count in his favour before hitting the pitch that he targets. This play style was taught to him by his former middle school coach which he detests but admits that it is something he cannot change or runaway from at this point. Ochiai thinks that with Okumura's catching talent and his leadership qualities, which is good enough to lead older players on the team, he can become a catcher that represents Tokyo if guided correctly.
- Koushuu ranked 11th in the First Official Character Popularity Poll.
- According to Yui most Daikyou senior people end up going to Kanagawa’s Kurebayashi or Tsuruta, yet Okumura joined Seidou.
- He doesn't have players he admires.
- He calls Seto Takuma Taku.
- After their quarrel Eijun gave him the nickname Wolf Brat. 
- Okumura (奥村) - Inner Village
- Koushuu (光舟) - Boat of Light
- "If he was the indisputable Ace and the Team's main stay, there is no way they would have subbed him out in a situation like that; that means he hasn't earned enough trust from the coach." - about Furuya 
- "And then your numbers. Once you complete them, I'm sure you'll become a pitcher everyone acknowledges." to Sawamura 
- "This person, who responds to the aggressive game calling by throwing pitches that exceed every expectation, is also quite something." - about Sawamura 
- "We're fighting in our own way." - to Sawamura
- "You're an eyesore, so can you do us a favor and remove yourself, senpai." - to Sawamura
|Seidou High School|
|Miyuki Kazuya • Maezono Kenta • Kuramochi Yōichi • Kawakami Norifumi • Asou Takeru • Nakata Ataru • Ono Hiroshi • Higasa Shōji • Seki Naomichi • Yamaguchi Ken • Kijima Rei • Kawashima Kengo • Shirasu Kenjirō • Mimura Ryōta • Watanabe Hisashi|
|Sawamura Eijun• Furuya Satoru • Kominato Haruichi• Kanemaru Shinji • Tōjō Hideaki • Kaneda Tadahiro|
|Yui Kaoru• Yūki Masashi • Okumura Kōshū• Mogami Takeshi • Asada Hirofumi • Seto Takuma • Kuki Yōhei
|Former players||Yūki Tetsuya • Tanba Kōichirō• Kominato Ryōsuke• Masuko Tōru• Isashiki Jun • Miyauchi Keisuke • Sakai Ichirō • Kadota Masaaki • Kusunoki Fumiya • Takigawa Chris Yū • Azuma Kiyokuni
|Managers||Fujiwara Takako • Umemoto Sachiko• Natsukawa Yui• Yoshikawa Haruno
|Staff||Kataoka Tesshin • Ochiai Hiromitsu • Takashima Rei • Kazuyoshi Oota|