Mars (2004)

Both are about a cool, very popular guy and a simple, but talented girl and how they due time get together.

Both FLs are withdrawn and both MLs are deeply troubled after causing or thinking they caused someone's death. Both FLs are able to see past the surface of the ML to the good person they are underneath. Both leads cross paths unexpectently and slowly help each other heal.

Both dramas involves school bullying with psychological issues making a tearful and gloomy atmosphere with sad events.

Both dramas are about two badly traumatized and emotionally fragile people who find healing in each other. Both MLs fear becoming evil and violent, both FLs are withdrawn.

I know! The stories in Mars and Love Shuffle doesn't have anything to do with each other but still..
Both dramas gave me the same feeling! They felt similar in some strange way!
So, if you liked the one I think you should definitely at least give a chance to the other! :)

Both FLs are somewhat isolated from the world, and the MLs are thought of as violent bad boys, but have good hearts. Both MLs feel responsible for someone's death, and unworthy of the FL. Both drama and movie have a similar feel.

Motorcycles are the main passion in both male characters. Both of them deal with the death of somebody very close to them.

Based on the manga "Speed Master" by Kishi Torajirou.
Akahoshi is a drifter with great car knowledge who travels from town to town aimlessly until he starts working at Sakurai Motors. The motor competition in town is tough though, and a battle between the top motor shop in town and Sakurai Motors soon ensues...