[Player Profile #29] Seko Ayumu | The Two-Way DF Raised in Taisho, Osaka — Le Havre AC's First Japanese CB
A deep dive into Seko Ayumu (25, from Taisho Ward, Osaka), who wears the No. 5 shirt as the first Japanese player in Le Havre AC's history. Trace his rise from Cerezo Osaka → Grasshopper → Le Havre as a versatile two-way player capable of playing both CB and defensive midfield.
Ayumu Seko, 25 years old. On July 22, 2025, upon the expiration of his contract with Swiss club Grasshopper, he joined French Ligue 1 side Le Havre AC on a free transfer, signing a two-year deal and becoming the club's first-ever Japanese player, wearing the number 5 shirt. In the 2025/26 season, he has made 24 league appearances, won the Monthly MVP award twice, and is a two-way centre-back who has dramatically improved the team's goals-against rate. Positioned in our editorial's predicted 26-man squad as "the fourth CB and a young challenger pushing for a place," we take stock of the expectations and challenges facing this defender with just under two months to go until the WC 2026 tournament.
menu_book Basic Profile
| Item | Details |
|---|---|
| Date of Birth | June 7, 2000 (25 years old) |
| Hometown | Taisho Ward, Osaka City, Osaka Prefecture |
| Height / Weight | 186 cm / 81 kg |
| Position | DF (two-way: Centre-Back / Defensive Midfielder) |
| Preferred Foot | Right (two-footed; high accuracy with left foot as well) |
| Club | Le Havre AC (Ligue 1, France) |
| Squad Number | Club: 5 / National team: 4 |
| International Experience | Senior debut in 2023; 12–13 caps, 0 goals |
arrow_forward Getting to Know His Roots
Taisho Ward in Osaka City is a working-class neighborhood with a geography resembling an "island" hemmed in by the Kizu and Shirinashi rivers. Long home to many migrants from Okinawa, it is known as "Little Okinawa." The Hirao Hondori shopping street, lined with eisa dance events and Okinawan specialty stores, a culture of river ferries, and the scenery of small manufacturing workshops are all part of everyday life there.
Seko attended Nakaizuo Elementary School in the ward and has roots playing football at local street clubs "Nakaizuo JSC" and "Foot Messe." A fateful step came when he followed his childhood friend Masao Ikeda (Kashima) to try out for Cerezo Osaka U-12 after Ikeda had joined the academy. A working-class town surrounded by the sea, rivers, and factory chimneys gave the world a 186 cm left-footed centre-back. His performance at the World Cup finals will be a source of pride for Taisho Ward.
calendar_month Career Timeline by Age
| Age | Period | Club / Key Events |
|---|---|---|
| 7–9 | 2007–2009 | Nakaizuo JSC / Foot Messe |
| 10–12 | 2010–2012 | Cerezo Osaka U-12 |
| 13–15 | 2013–2015 | Cerezo Osaka U-15. Won the Prince Takamado Trophy JFA U-15 All-Japan Championship (2015) |
| 16–18 | 2016–2018 | Cerezo Osaka U-18 / Kokoku High School / second-team registration |
| 16 | May 24, 2017 | First-team debut (Levain Cup vs. Kobe; youngest-ever club debut at 16 years and 11 months) |
| 18 | October 2018 | Signed professional contract with Cerezo Osaka |
| 20 | 2020 | Won both the J1 Best Young Player Award and the Levain Cup New Hero Award |
| 21–25 | Jan 2022 – Jun 2025 | Grasshopper (Switzerland). 117 Super League appearances, 1 goal |
| 25 | From Jul 22, 2025 | Le Havre AC (Ligue 1, France). First Japanese player in club history |
local_fire_department 2025/26 Season: Dramatically Improving Le Havre's Goals-Against Rate
In the summer of 2025, Seko joined Le Havre AC on a free transfer from Grasshopper in Switzerland. As the club's first-ever Japanese player and wearing the number 5 shirt, he became a defensive cornerstone from his very first season.
In the 2025/26 Ligue 1 season, he has made 24 appearances with a FotMob average rating of 6.81, ranking among the team's best in every defensive metric — tackles, interceptions, and clearances. He has won the club's Monthly MVP award twice (October 2025 and January 2026).
Most tellingly, the goals conceded data speaks for itself. After shipping 71 goals in 34 games the previous season, Le Havre dramatically tightened up in the 2025/26 campaign, conceding just over 2 goals per 19-match stage — an improvement directly attributable to Seko's arrival.
| Season | Club | League Apps | Goals |
|---|---|---|---|
| 22-23 | Grasshopper | 31 | 0 |
| 23-24 | Grasshopper | 36 | 1 |
| 24-25 | Grasshopper | 37 | 0 |
| 25-26 | Le Havre | 24 | 0 |
sports_soccer International Career — Survival from the Fourth CB Spot
Seko made his international debut on March 24, 2023, playing the full 90 minutes in a 1-1 draw against Uruguay. He also came on as a substitute against Peru on June 20, but subsequently fell out of the national team picture.
In June 2025, he was called up to return to Osaka for a national team camp on his 25th birthday for the match against Australia, where he conceded the decisive goal immediately after coming on in added time at the end of the second half. He took full personal responsibility, saying "It was my fault" and vowing to "take more responsibility." Backed by his strong club form at Le Havre, he was also called up for the September tour of North and Central America (matches against the USA and Mexico) and earned starting opportunities.
Our editorial's reasoning for placing him as "the fourth CB" lies in his uniqueness compared to players like Tomiyasu or Machida — his ability to play with both feet and fill a defensive midfielder role, making him a genuine two-way option. Alongside Junnosuke Suzuki and Kodai Takai, he is fighting "the final battle for survival."
star Ayumu Seko in a Word — "The World Changes from the Left Foot" and "Two-Way Defender" in Coexistence
There are two essential keywords for understanding Seko.
| Keyword | How It Shows Up in His Game |
|---|---|
| The world changes from the left foot | Two-footed despite being right-handed, with high left-foot accuracy / diagonal long balls from left CB to instantly release Mitoma and Ito / Paris Normandie described it perfectly: "When European scouts came to watch an attacking genius, they stumbled upon a top-level defender by chance" |
| Two-way defender | High-level flexibility switching between CB and holding midfielder / Top in team for distance covered, combining physicality with reading the game at over 30% duel win rate / His "detective-style" reading of the game is even backed up by the story of how Detective Conan inspired him to play football |
The value of combining both qualities is clear — "defend and also be a launch pad." He embodies the modern CB archetype, providing that range of options to Moriyasu's Japan.
favorite Expectations at WC 2026 — The Key to Japan Breaking Out of Group F
Japan are in Group F alongside the Netherlands, Sweden, and Tunisia. Seko is expected to play a role as a positionally flexible joker alongside or in limited deployment with Machida and Ito, leveraging his defensive-midfielder background.
| Opponent | Key Striker Type | Role Expected of Seko |
|---|---|---|
| Netherlands | Depay / Haavik-style CF | Use his 186 cm / 81 kg frame to cover the space in behind while switching play with left-footed long balls |
| Sweden | Isak-style tall striker | Serve as an aerial threat alongside Machida to win set-piece duels |
| Tunisia | Pace-based wide forwards | Use his defensive-midfielder's reading to kill space, and serve as a build-up outlet with his feet |
live_tv Social Media & Media Presence
Seko's communication style is cool and stoic. In an exclusive interview with France's L'Équipe, he spoke about how "Detective Conan inspired me to play football. I was in awe of the scene where Conan kicks the ball by pressing a button on his belt. My bookshelf was full of manga," which became a talking point. His nickname is "Secom" (a nod to his rock-solid defending). He is the type who speaks candidly, but what lies beneath is a genuine desire to overcome challenges.
info The Challenge to Overcome: "Conceding Goals at International Level"
Conceding goals at international level — this is the single biggest challenge facing Seko. He has the track record of giving away the decisive goal after coming on against Australia, and his composure in critical moments and overall experience remain under scrutiny. His relatively limited international record of approximately 13 caps is also something that cannot be overlooked.
In January 2026, he also suffered a broken rib in a match against RC Lens, and the fierce determination that kept him running even when "the bones were clicking" conversely raises concerns about managing his physical condition. How well he can establish himself as "Moriyasu's positionally flexible joker" — first at the Kirin Challenge Cup match against Iceland on May 31 and then at the pre-tournament training camp — is the final mission set before him.