The top joshi star right now is easily Saya Kamitani. She is the Red Belt Champion of Stardom, which is the highest title in the company. The last two matches in OP are hers and area really worth watching if any of this interests you at all. They are both against her mentor, who lifted her when she was at her lowest and whom she defeated to take the belt.
https://www.youtube.com/watch?v=rzc1AO_3vVU