Games played by Jun Koyama (Tokyo, Japan) in this fuseki

5
42
1
3
4bw
+3 
=  
- 1
?  

1Koyama Jun - Isobe Seiji
2Koyama Jun - Topkin Georg-Romet
3Koyama Jun - Miyamoto Syunju
4Nakamura Shigeru - Koyama Jun