Fumihiro Aoyama was living a blissful life with the love of his life, Ema. They even promised to marry each other after their graduation. However, the tranquility of their lives shatters when betrayal strikes, leaving Fumihiro entangled in a web of dark emotions. As new characters emerge with their own painful pasts, the story weaves a tapestry of love, forgiveness, and rebirth. Navigating the challenges of everyday life, Fumihiro must overcome the pain of betrayal and rediscover the light within. Passions entwine, secrets surface, and Fumihiro's heart is torn between the past and the present. "I Thought I Could Be Happy" is an exhilarating journey through the intricate fabric of human relationships, where pain transforms into hope, and rebirth takes unexpected forms. Will Fumihiro rise from the ashes of his pain, or will the weight of betrayal prove too much to bear? Or will he get his revenge?