It could be Orochimaru. Since he is always scheming and has a lot of power, Naruto could be reliving a day where Orochimaru is about to launch a major attack on the village. Each day, Naruto has to figure out how to stop Orochimaru's different plans, whether it's his experiments, his infiltration attempts, or his attempts to steal jutsu.
A really unique plot could be Naruto living the same day as the day Sasuke leaves the village. He could keep trying different things to stop Sasuke. Some days he might try to talk to Sasuke more about their friendship, other days he could try to prevent Orochimaru's influence from reaching Sasuke, which would be a very emotional and character - driven story.
One interesting concept could be the characters reliving the same day repeatedly. For example, Naruto might keep waking up to the same day and have to figure out how to break the cycle. It could also show how different characters react to the time loop. Some might be frustrated while others might try to use it to their advantage, like Sasuke using the extra time to train more intensively.
Naruto himself would likely be a main character. Since he is the protagonist of the Naruto series, the Groundhog Day concept would be interesting to apply to him. He could be the one stuck in the time loop, trying to figure out what's going on. Sasuke is also a likely main character as he has a complex relationship with Naruto. His reactions to Naruto being in the time loop and how he might be involved in breaking it could be a big part of the story.
The Groundhog Day origin has its roots in European weather lore. When settlers came to America, they brought this tradition. Groundhog Day is on February 2nd. Legend has it that if the groundhog emerges from its burrow and sees its shadow, there will be six more weeks of winter. If it doesn't, spring will come early. It's a fun and unique cultural tradition that has been passed down over the years.
Groundhog Day is a story about a man who gets stuck in a time loop, reliving the same day over and over. It's a humorous and thought-provoking concept that explores themes of self-improvement and finding meaning in life.