There's the story of a Magikarp that was constantly made fun of for being 'useless'. It tried so hard to be strong but was always overlooked. However, it didn't give up and eventually evolved into a powerful Gyarados, but all those years of being mocked were really sad. Magikarp was often bullied by other Pokemon in the pond, and trainers would release it quickly thinking it was worthless. But it had a hidden potential that took a long time to be recognized.
One sad Pokemon story could be about a trainer abandoning their Pokemon. For example, a trainer might leave their old and weak Pokemon in the wild because it couldn't keep up in battles anymore. The Pokemon would be left alone, confused and sad, having known only the company of the trainer before.
One sad shiny pokemon story could be about a shiny pokemon that was separated from its trainer during a storm. The trainer searched everywhere but couldn't find it. The shiny pokemon, alone and scared, had to fend for itself in the wild, constantly looking for its beloved trainer.
Another sad shiny pokemon story involves a shiny pokemon that was born with a defect. This made it not as strong as other shiny pokemon. Other trainers would always overlook it when choosing pokemon. It felt unwanted and unloved, spending most of its days alone in the tall grass, hoping that one day someone would see its value beyond its defect.
Mimikyu has a rather sad story too. Mimikyu is very lonely because it is so different. It wears a ragged cloth to look like Pikachu in an attempt to make friends. However, most pokemon are scared of it when they see its true form under the cloth, which makes it even more isolated and sad.
Another story could be about Lopunny. Lopunny is a very cute and energetic Pokemon. In some stories, its playfulness and friendly nature make it a popular and somewhat'sexy' (in terms of charm) Pokemon among trainers and in the Pokemon community.
One sad addiction story is about a person addicted to gambling. He lost all his savings, his family's trust, and his job. His addiction made him lie constantly and pushed away all his friends. Eventually, he hit rock bottom and realized the enormity of his mistake when he had nothing left.
One sad ICU story is about a young mother. She was in a car accident and ended up in the ICU. Her little children were waiting outside, not fully understanding what was going on. Despite the doctors' best efforts, she passed away, leaving her family in deep grief.
One sad bff story is when my best friend moved to another country for her parents' job. We had been inseparable since childhood. We used to do everything together, from going to school to sleepovers. When she left, it felt like a part of me was gone. We still keep in touch, but it's not the same as having her here beside me.
One: 'Found love. Lost it. Alone.'