Fairy Tail Wiki:Relación Seis/Thunder Gods

Lucy Heartfilia
Natsu is the person who brought Lucy to Fairy Tail and has described her as a nice person. Natsu and Happy always go on missions with Lucy and have the tendency to break into her house anytime of the day. Although he usually teases her, Natsu actually cares for Lucy very much. They have become very close friends, even to the point where he cried when he thought Lucy was leaving the guild after the incident with Phantom Lord. He often saves her when she is in trouble, such as when he saved her when she got captured by Bora, then when she was captured by Jose Porla and when she was captured and beaten by Gajeel Redfox. During their time in Edolas, when he heard that she was about to be executed, he got angry and he threatened to kill the guards if they touched her. During the S-Class Trial, he also protected Lucy from being killed by Kain and then decides to form their team temporary to defeat Grimoire Heart. He was supportive of Lucy when she was told of her father's death, and brought a job to help her pay her rent and cheer her up.

Erza Scarlet
Erza Scarlet friend of Natsu and part of Team Natsu share a very close bond. When Natsu first introduced Erza, he described her as a scary, omnipotent person and he also feared her. Natsu always admires her strength, determination, courage and Natsu has been eager since long to battle Erza to see the stronger one. There is a friendly rivalry between those two.

Erza and Natsu has been along since childhood. They even took a bath together along with Gray Fullbuster. Both Erza and Natsu care for each other and will protect each other to death. Erza acts as an insulator when Gray and Natsu fight. Natsu starts behaving like Happy saying "Aye" when Erza talks to him due to the fear.

Natsu admires the strong and dauntless Erza, he was enraged to see that due to Jellal, Erza was shredding tears as if she was weak. Seeing this, Natsu knocks Erza unconscious promising that when she wakes up, her nightmare would be over. With this lionhearted vehemence, Natsu succeeds in defeating one of the Ten Wizard Saints again showing that Natsu would destroy all impediments that makes Erza desperate.

Natsu and Erza are the same when it comes to Fairy Tail, they have really strong feelings for their guildmates. In the Tower of Heaven arc, Natsu says to Erza even if he does not know much about her past, he is just like her; A world without his friends would have been impossible.

Gray Fullbuster
Gray Fullbuster is a guild mate as well as a fellow teammate of Natsu. The two share a competitive and, at the same time, very close relationship. Gray is considered Natsu's main rival and the two Mages have fought constantly even since their younger years. Despite the fact that they are constantly fighting with one another, they are extremely close, and have been since they were small. They even showered together along with Erza Scarlet as young children. The two truly care for each other and will do anything in order to protect each other. During their time on Galuna Island, Natsu stopped Gray from killing himself twice. And later, while they were in the Tower of Heaven trying to defeat Jellal Fernandes and his minions, Gray saved Natsu from being devoured by Trinity Raven member, Fukuro.

Mirajane Strauss
Natsu and Mirajane's current relationship is a friendly one, much like Mirajane's relationship with every other member in the guild. When she was younger, however, Mirajane was very antagonistic towards Natsu. He was a member of "Erza's group" as Mirajane called it, and so she teased him endlessly. Despite this, she's always held a soft spot for him, finding him to be cute when he cries, and generally kept tabs on him in Erza's absence.