Kosei Suwama

Season	Club	Apps	Match	RTG	Season
2027/28	Yokohama F. Marinos · 5th	3	6.8	44	4
2026/27	Yokohama F. Marinos	7	6.81	—	—
2024/25	Yokohama F. Marinos	1	6.3	—	—
2024/25	Tsukuba University	1	—	—	—
2022/23	Tsukuba University	1	—	—	—

Domestic-league totals per season. RTG = Field Insider Rating (potential / ceiling); Season = age-blind form that year.

Japan · international

Side	Apps	G
Japan U20	1	0

Career caps & goals — tournament breakdown in the full career.

Scout report

★ Standout performer

All J1 League standouts →

First senior season on record — and already on the pitch for 100% of Yokohama F. Marinos's available minutes, one of the top game-time debuts in the J1 League this season.

Squad depthCentral defender

K. Suwama is a 23-year-old central defender at Yokohama F. Marinos, rated 46.1 overall by Field Insider's model. An emerging talent, he has been a fringe squad member this season (15.8% of available minutes). His defensive output reads 2 tackles, blocks and interceptions per 90. Below: strengths, watch-points, market-value outlook and the latest transfer news on Suwama.

On the season, Suwama graded 15 for current form (age-blind), on 2 clean sheets and 2 defensive actions per 90.

We hold a single season for Suwama, so there's no year-on-year comparison to draw yet — the read above is this campaign only.

On long-term talent our Rating reads 46. At 23 Suwama is still climbing toward his ceiling, and a market index of 12.6 reflects that trajectory.

46.1

Ratingi

a solid contributor and squad regular

14.5

Seasoni

below regular-starter level

15.8%

Minutes

limited game time

Def. actions / 90

moderate defensive volume

Output in context · Yokohama F. Marinos finished 5th of 20 · an upper-table side

Apps

Def. / 90

—

Tackles

Interceptions

Clean sheets

2 tackles, blocks & interceptions per 90 — moderate defensive volume, with 2 clean sheets across 3 appearances. Behind an upper-table side (5th of 20) the side controls more games, so the defensive load is lighter — the value sits as much in composure and ball progression as in raw volume.

Watch points

Game time. Only 15.8% of available minutes — needs a settled run to prove the level.

Outlook

Rated 46.1 overall — a solid contributor and squad regular. Defensively he reads as moderate defensive volume (2 tackles, blocks & interceptions per 90). Approaching peak years; value is still building (price multiplier 2×) with the best seasons likely ahead.

Generated from Field Insider's rating model · AI-written analysis to follow.

Per 90 & availability

Minutes played %15.8%

Available fixtures3 of 3

Goals / 900

Assists / 900

Goal contribution / 900

Defensive actions / 902

Player flow

Goal involvements0

Pass accuracy %83

Dribble success %100

Cards / 900

Foul involvement / 901.667

Value & potential by age

Market valueRating

Solid = now · dashed = projected

The gold line is market value — an index (not €) blending rating, age and league. It climbs through the early 20s, peaks around ages 23–27 (~13), then tapers with age. At 23, Suwama sits on 12.6, at or near its peak. The blue line is Suwama's projected Rating — 46.1 today — recomputed at each age, so it follows the same rise-and-fall as a career matures and declines. Solid = up to today; dashed = projected.

Transfer history

Yokohama F. MarinosFeb 2025 – now

TTomori Beratuntil Feb 2025

Yokohama F. MarinosFeb 2025 – Feb 2025Free

TTsukuba Univ.until Feb 2025

TTsukuba University(back from loan)Jun 2024 – Feb 2025

Yokohama F. MarinosFeb 2025 – Jun 2024Free

Yokohama F. Marinos(on loan)Jan 2024 – Feb 2025

TTsukuba Universityuntil Jan 2024

About K. Suwama

Kosei Suwama is a 23-year-old centre-back who plays for Yokohama F. Marinos, born on June 6, 2003, standing 186 cm tall. He is from Japan. Yokohama F. Marinos currently sit 5th of 20 in the J1 League.

This season

In the current season, K. Suwama has made 3 appearances with 0 goals and 0 assists across 270 minutes.

K. Suwama's next match is on September 2, 2026, when Yokohama F. Marinos face Kyoto Sanga at home in the J1 League.

Field Insider's view

Field Insider currently rates K. Suwama at 46.1 with a Season form score of 14.5. See the full scout report for strengths, watch-points and the market-value outlook.

Career

Across 4 recorded seasons, K. Suwama has totalled 13 club appearances with 0 goals and 0 assists for 2 different clubs. His busiest campaign came in 2026/27, with 7 appearances for Yokohama F. Marinos.

K. Suwama's career has also included time at TTomori Berat, TTsukuba Univ. and TTsukuba University.

On the international stage, K. Suwama has represented Japan U20 — 1 cap in our records.

Transfer news

No transfer news found for this player.