The statement 'grudge is real story' is rather ambiguous. There could be a story that is based on real - life grudges that someone has experienced and then fictionalized. Or it could be a misnomer for a well - known horror franchise. Without more details, it's hard to say for sure if it's a real story in the sense of being based on actual events. But grudges in general are real in the realm of human emotions and interactions.
I'm not entirely sure which specific 'grudge' story you're referring to. There are many stories and movies with 'grudge' in the title. If it's 'The Grudge' in general, it's often a fictional horror concept, but it might draw on some common fears and superstitions that exist in various cultures.
If 'grudge is real story' implies a particular story about grudges being real, well, grudges are very much a real psychological phenomenon. People can hold long - lasting resentments in real life, which can sometimes lead to real - world consequences like damaged relationships or even acts of revenge. However, if it's about a specific narrative, more context is needed.