| 1 | A | B | C | D | E | F | G | H | I | J | K |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 2 | Akinori Kosaka - Club statistics |  |  |  |  |  |  |  |  |  |  |
| 3 | Club performance | Club performance | Club performance | League | League | Cup | Cup | League Cup | League Cup | Total | Total |
| 4 | Season | Club | League | Apps | Goals | Apps | Goals | Apps | Goals | Apps | Goals |
| 5 | Japan | Japan | Japan | League | League | Emperor's Cup | Emperor's Cup | J.League Cup | J.League Cup | Total | Total |
| 6 | 1998 | Omiya Ardija | Football League | 23 | 9 | 3 | 0 | - | - | 32 | 9 |
| 7 | 1999 | Omiya Ardija | J2 League | 22 | 2 | 3 | 3 | 1 | 1 | 26 | 6 |
| 8 | 2000 | Omiya Ardija | J2 League | 21 | 2 | 1 | 0 | 2 | 0 | 24 | 2 |
| 9 | 2001 | Omiya Ardija | J2 League | 23 | 4 | 1 | 0 | 1 | 0 | 25 | 4 |
| 10 | 2002 | Omiya Ardija | J2 League | 10 | 0 | 0 | 0 | - | - | 10 | 0 |
| 11 | Country | Japan | Japan | 99 | 17 | 8 | 3 | 4 | 1 | 111 | 21 |
| 12 | Total | Total | Total | 99 | 17 | 8 | 3 | 4 | 1 | 111 | 21 |

Question: When did Akinori Kosaka join the Japan Football League club?
Answer: Akinori Kosaka joined Japan Football League club Omiya Ardija in 1998.