"Precure All Stars New Stage 2: Kokoro no Tomodachi" is a crossover film that brings together the Pretty Cure heroines from various seasons, continuing the narrative established in the "Precure All Stars" series. The story centers on the bond of friendship and the challenges that arise when it is tested. The film introduces a new character, Cure Echo, who plays a pivotal role in the unfolding events.

The narrative begins with the Pretty Cure teams enjoying a peaceful day at a theme park, celebrating their friendships. However, their tranquility is disrupted by the appearance of Fusion, a mysterious entity that feeds on negative emotions and seeks to destroy the bonds between friends. Fusion creates dark versions of the Pretty Cure heroines, known as Dark Precure, who embody the doubts and insecurities of the original characters. These Dark Precure challenge the heroines, forcing them to confront their inner struggles and the strength of their friendships.

As the Pretty Cure teams battle their dark counterparts, they are joined by Cure Echo, a lone warrior who has lost her memories and struggles to understand her purpose. Cure Echo’s presence becomes crucial as she helps the heroines realize that their bonds are stronger than any negativity. Together, they work to overcome Fusion’s influence and restore harmony.

The climax of the film involves a collective effort by all the Pretty Cure teams, combining their powers to defeat Fusion and its manifestations. The resolution emphasizes the importance of trust, understanding, and the enduring power of friendship. Cure Echo’s journey also reaches a poignant conclusion as she regains her memories and finds her place among the Pretty Cure heroines, solidifying the theme of unity and emotional resilience.

The film features a large ensemble cast, including iconic characters from previous "Precure" series such as Cure Black, Cure White, Cure Bloom, and Cure Egret, among others. Each character contributes to the overarching narrative, showcasing their unique abilities and personalities while reinforcing the central message of the story. The interactions between the heroines highlight their growth and the unbreakable bonds they share, making "Precure All Stars New Stage 2: Kokoro no Tomodachi" a celebration of the franchise’s enduring themes of friendship and teamwork.