Kumiko Iijima defeated Natsumi Hamamura 3-6 6-3 7-5 in the Makinohara 25K round of 32 on carpet. The result followed the form book — Kumiko Iijima came in leading the head-to-head 3–2. Kumiko Iijima extended the head-to-head to 4–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2010-05-17 | Karuizawa 25K | SF | carpet | Natsumi Hamamura | 6-3 1-6 7-5 |
| 2007-06-11 | Guangzhou 50K | QF | hard | Kumiko Iijima | 7-6(2) 7-6(3) |
| 2007-05-28 | Gunma 25K | F | carpet | Kumiko Iijima | 3-6 6-3 7-6(3) |
| 2007-05-21 | Nagano 25K | R16 | carpet | Natsumi Hamamura | 6-4 4-6 7-5 |
| 2006-07-31 | Tokachi 250K | R16 | carpet | Kumiko Iijima | 7-6(4) 6-3 |