On April 18, 2015, Fighting Girls 13 "Spring Thunder: Climactic Battle of Generational Struggle" took place. Centered around a theme of new versus old, this highly anticipated event featured dual title matches for both the B-1 and FG championships. B-1 Champion Panther Risako faced Yuto Akagi, while second-generation FG Champion Mao Kaneshiro battled Masako Natsume. Additionally, Marie Konishi, the victor of the Fresh Start Tournament, made her appearance. With such a stellar lineup, this event brought a fresh wave to the fighting scene.
The opening match pitted rising star Ruru Aozawa against active gravure idol Haruka Amami. Viewed as a crucial bout indicating FG's future direction, this fight was expected to lean less on rigid pro-wrestling style and more toward a raw, catfight-style realism. The intense clash between the two promised unpredictable developments and an uncertain outcome.
In the second match, 170cm tall Kana Hasumi faced the petite Yuki Shiina. While Hasumi held a clear advantage in physical ability, Shiina could counter with superior stamina and aggression. Though their skill levels differed, both fighters aimed for stardom, holding the potential to deliver a match worthy of hardcore fans—particularly one appealing to seasoned viewers.
The third match featured Fresh Start Tournament 2015 champion Marie Konishi against FG-native gravure idol Shiroinko. Konishi, a proven talent handpicked by FG, squared off against Shiroinko, known for her seductive figure and dominant S personality. Both fighters were highly rated, setting the stage for a battle where mutual respect and escalating intensity were guaranteed. The evolution of their skills made this clash a major highlight.
In the semifinal, the B-1 Title Match saw reigning champion Panther Risako defend her black belt against challenger Yuto Akagi. Panther carried the legacy of the black belt lineage, while Akagi drew attention as a rookie making her FG debut. A victory would elevate Akagi to superstar rookie status and potentially reshape the narrative of the entire promotion, making this a pivotal match whose outcome could drastically alter the story's course.
The main event featured the FG Title Match between undefeated absolute champion Mao Kaneshiro and challenger Masako Natsume. Kaneshiro, an undefeated dominant force, had previously defeated an elite roster within FG. Natsume, on the other hand, had suffered a loss in her first challenge at the FG dojo match but used that humiliation as fuel, going on a winning streak to earn her spot in the main event. This match focused on whether Natsume could achieve revenge against her senior or if Kaneshiro would continue her legacy as the strongest. This decisive battle was set to kick off a year of upheaval in 2015.