Nanami Momozono and Tomoe are the main couple of "Kamisama Kiss". Nanami is a young high school girl who becomes the new Land God of the Mikage Shrine and Tomoe is a fox yokai who becomes her familiar.

Nanami is a typical normal human girl, but comes from a difficult family, having lost her mother at a young age and her father with a serious gambling problem. In spite of her problems, Nanami is a kind, caring and highly spirited and determined young girl with a flourishing beauty. Tomoe is a fox yokai who was once originally a wild fox, pleasing himself by doing whatever he wanted and was once partnered with another yokai, Akura-Oh. However, Tomoe's past also shrouds in mystery when he left his old life behind and became the familiar to Mikage, until one day 20 years earlier, Mikage left the shrine with no explanation, apparently abandoning Tomoe, leaving him deeply saddened, unaware that Mikage has a secret plan set into motion.

Nanami and Tomoe first met when Nanami was bestowed the mark of the Land God by Mikage, who offered Nanami his home after her father abandoned her and left her homeless. Nanami and Tomoe did not get along well in the beginning as Tomoe refused to accept Nanami as the new Land God, believing her to be unfit for the role, but was forced to obey her once she sealed the familiar contract with a kiss. Nanami and Tomoe are known to constantly bicker and fight with each other, but despite their differences, they begin to form a close relationship, the more they spend together. Tomoe always protects Nanami whenever she is in danger and even goes so far as to attend high school together in order to keep her safe from yokai attacks while helping to raise her power as a god. Nanami begins to realize that despite Tomoe's harsh attitude, he is truly very kind at heart, appreciates all that he does for her and starts to notice how much he misses his former master, Mikage. Nanami also gains insight into Tomoe's past life as a wild fox, briefly having a time traveling adventure, where she comes to fully appreciate the Tomoe she knows in the present compared to his past self.

Over time, both Nanami and Tomoe continue to grow closer and truly come to care and worry about one another. Eventually, both Nanami and Tomoe begin to develop romantic feelings for each other and later realize they have fallen in love. Nanami is the first to realize her true feelings, but becomes heartbroken when Tomoe rejects her, but in spite of this, Nanami resolves to continue expressing her feelings. However, Nanami is upset to learn that Tomoe was once in love with a human women named, Yukiji, when he was still a wild fox and long before he became Mikage's familiar. Due to this, Nanami feels she can never compare to Yukiji and is jealous of their past together, but despite this, Nanami refuses to give up on her feelings. Tomoe was both oblivious and in denial about his true feelings for Nanami, but slowly yet surely, Nanami's warmth and kindness works it's way into his heart and Tomoe becomes impressed with her growth and how far she's come in her role as a land god.

By the second season, Tomoe finally realizes he is in love with Nanami, becoming more protective than ever and also show signs of jealously of other romantic rivals, but is unable to admit how his feelings for her. Nanami remains oblivious to Tomoe's feelings and becomes concerned after learning more of his past with Yukiji, discovering Mikage used his powers to seal away Tomoe's memories and love of her and brought him and Nanami together to help Tomoe to better understand humans. Throughout the rest of the season, Tomoe's love for Nanami grows stronger, secretly yearning to be with and protect her while also trying to respect her wishes. Nanami's feelings for Tomoe remain and deepen, showing her devotion and dedication to him and turns down those who express a romantic interest in her.

In "Kamisama Kiss: Kako-hen", Nanami and Tomoe's relationship takes a major step forward when Nanami finally comes to learn Tomoe is in love with her, but in a shocking turn of events. Upon finally realizing his love for Nanami, the seal that Mikage once placed upon him is broken, bringing back his memories of Yukiji, but also a curse. In order to truly be with Yukiji, Tomoe wished to become a human and made a deal with a fallen god, but when Yukiji was killed, Tomoe was slowly dying from his curse since he was unable to fulfill his promise to spend his life with the woman he loved. Nanami learns of the curse as well as Tomoe's feelings for her and begins to blame herself for the curse returning. However, Nanami is determined to find a way to save Tomoe and plans to travel back in time to prevent him from making the deal and therefore save his life, even at the risk they might never meet each other.

Eventually, Nanami begins her journey back in time to meet the fallen god who bestowed the curse on Tomoe so she may find a solution in the present. In the past, Nanami encounters Yukiji and Tomoe, but their relationship is far different than originally assumed with the discovery that Yukiji holds a great disdain and hatred toward yokai and is planning to marry a wealthy lord. Nanami meets Tomoe in the past after she finds and rescues him in his efforts to escape after sustaining a serious injury and takes his child form to stay safe. Tomoe is taken back to Yukiji's home in order to recover, but Nanami tries to keep her distance from Tomoe to ensure she will not interfere in his relationship with Yukiji, but instead secretly visits him at night. During this time, Tomoe becomes infatuated with Nanami, but mistakes her for Yukiji. He wants her for himself and his feelings are so strong to the point he stops himself from attacking Nanami, despite her frail and weak condition due to the effects time traveling has taken on her body.

Ever since, Tomoe is unable to get Nanami out of his mind, but remains oblivious to the truth about his feelings for her and denies when others realize he has fallen in love. When Tomoe's partner-in-crime, Akura-Oh learns about Yukiji and wants her for himself, Tomoe disrupts his plan as he still wants "Yukiji" for himself. To ensure Yukiji's safety against Akura-Oh, Nanami takes her place and disguises herself in the wedding procession and during this time, Nanami once again encounters Tomoe after she escapes from Akura-Oh's minion and they take shelter. Tomoe declares intentions that he wants Nanami for himself, but Nanami refuses due to his arrogant and forceful behavior. Although he leaves Nanami to fend for herself, Tomoe remains close, believing she will come back to him and once again protects her from bandits. Nanami begs Tomoe to spare them and assures she does not hate him, stunning Tomoe.

Following this event, Nanami and Tomoe grow closer and Tomoe attempts to make her change her mind about the marriage to the lord.

Following these events, Nanami is determined to save Tomoe and remove the curse once and for all. In Nanami's efforts, she travels back in time and through a series of events, it's learned that Tomoe had actually fallen in love with Nanami in the past when she traveled back in time and disguised herself as Yukiji. Afterwards, Tomoe's curse is finally broken, reuniting him and Nanami and becoming a couple at last. By the end of the series, Tomoe's wish is granted and is turned into a human, allowing him and Nanami to be together and later get married and become parents.