One example is the story of 'Taketori Monogatari' (The Tale of the Bamboo Cutter). In this story, the celestial princess Kaguya - hime has a name that is not only long but also very evocative. Her name is associated with the moon, and the entire story revolves around her. Her long name gives her an air of mystery and divinity which is in line with her character as a celestial being who descends to the mortal world.
Another story could be from the Edo period literature. There were some fictional stories where the samurai characters had long names. For instance, a samurai might be named 'Tokugawa - no - Masamune - the - Valiant - Sword - Wielder'. This name combines the family name (Tokugawa), a personal name (Masamune), and a description of his skill with the sword. The long name helps to establish the character's identity within the context of the story, showing his family lineage, his own name, and his notable ability.