On at Jewels 1st Ring, Ishikawa debuted with a victory over Sumie Yamada via submission in 62 seconds. Fighting as a freelancer at Jewels 5th Ring on, Ishikawa defeated Asako Saioka with a rear naked choke submission in less than 90 seconds. Ishikawa was originally set to fight against Mami Odera as part of the 2009 Jewels -48 kg Rough Stone Grand Prix, but Odera was injured before the bout and Ishikawa was given direct entrance to the final and fought instead in a regular match at the event. In the final of the 2009 Jewels -48 kg Rough Stone Grand Prix, Ishikawa was defeated by Asami Kodera via unanimous decision at Jewels 6th Ring on. In her second consecutive loss, Ishikawa lost against Miyoko Kusaka by split decision on at Jewels 7th Ring. Training with Reversal Gym Yokohama Ground Slam, Ishikawa rebounded with a victory over Misaki Ozawa via submission in the first round during the 2010 Jewels -48 kg Rough Stone Grand Prix semi-finals at Jewels 10th Ring on. On at Jewels 11th Ring, Ishikawa won the 2010 Jewels -48 kg Rough Stone Grand Prix by defeating Yukiko Seki in the tournament final via split decision. Ishikawa faced Sachiko Yamamoto in a Jewels vs. Valkyrie match at Jewels 15th Ring on. She defeated Yamamoto by unanimous decision. Ishikawa faced Yasuko Tamada in the opening round of the Jewels Featherweight Queen tournament at Jewels 16th Ring on in Tokyo. She defeated Tamada by unanimous decision. Ishikawa then faced Naho Sugiyama in the semi-finals of the tournament at Jewels 17th Ring on. She was defeated by split decision. Ishikawa competed in Okinawa for the first time when she faced Shino VanHoose at Pancrase Progress Tour 6 on. She won the fight by unanimous decision. Ishikawa was scheduled to face Angelica Chavez at Invicta Fighting Championships 2 on in Kansas City, Kansas. On, it was announced that Ishikawa would no longer be competing on the card. On, Ishikawa faced Tomo Maesawa at Jewels 22nd Ring. She defeated Maesawa by unanimous decision. Ishikawa faced Miyoko Kusaka in a rematch at Pancrase: Sakaguchi Dojo vs. Pancrase on in Okinawa, Japan. She defeated Kusaka by TKO in the first round. On, Ishikawa returned to Pancrase to face American opponent Amber Brown at Pancrase 250. She was defeated by submission due to an armbar in the third round.
