Friendship and faith, love and betrayal . . . and guilt. Rumbling Hearts weaves a tale not of superheroes or science fiction, but of the silent sufferings of any potential passerby. This is real life. Happy endings are bittersweet at best.
Meet four fast high school friends — Haruka, Takayuki, Mitsuki, and Shinji. Life's promise shines brightly on these companions, until one day a random accident leaves Haruka in a coma. Her boyfriend, Takayuki, cannot forgive himself and seems determined to follow Haruka into a comatose state. Mitsuki dedicates her life to taking care of this tragic young man, and the pair salvage what they can, falling into a self-destructive relationship floundering in guilt. When Haruka awakens three years too late suffering from anterograde amnesia, everyone has to act as if not a day has passed. Torn between his unhappy real-life train wreck with Mitsuki and the warm and fuzzy daydream high-school romance with Haruka, Takayuki watches what little silver lining was left in life be mercilessly and methodically stripped away.