Morigami has won 1 singles title in her career, defeating top-seed Marion Bartoli of France 6–1 6–3 in Prague in 2007. She has reached two other singles finals, both in Cincinnati (falling to Patty Schnyder in 2005, and losing to Anna Chakvetadze in 2007). In the 2006 French Open, she upset then-World No.3 Nadia Petrova in the first round. Petrova was a favorite to win the Grand Slam title. She is known for her strong two-handed game.
| Legend (Singles) |
| Grand Slam (0) |
| Tour Championships (0) |
| Tier I Event (0) |
| Tier II Event (0) |
| Tier III Event (0) |
| Tier IV Event (1) |
| ITF Circuit (7) |
| No. | Date | Tournament | Surface | Opponent in the final | Score |
| 1. | March 12, 2000 | Warrnambool | Grass | Mireille Dittman | 6–4 5–7 6–1 |
| 2. | March 26, 2000 | Wodonga | Grass | Mareze Joubert | 6–1 6–1 |
| 3. | October 14, 2001 | Saga | Grass | Nana Miyagi | 6–4 7–5 |
| 4. | October 28, 2001 | Home Hill | Hard | Mireille Dittman | 0–6 6–4 6–1 |
| 5. | April 27, 2003 | Dothan | Clay | Milagros Sequera | 6–3 6–4 |
| 6. | June 6, 2004 | Surbiton | Grass | Anna Chakvetadze | 6–4 1–6 6–1 |
| 7. | May 7, 2007 | Prague | Clay | Marion Bartoli | 6–1 6–3 |
| 8. | November 4, 2007 | Taoyuan | Hard | Yanina Wickmayer | 6–4 7–6(5) |