RenEur

RenEur is the het ship between Renton Thurston and Eureka from the Eureka Seven fandom.

Canon
Renton and Eureka's relationship is the most complex throughout the story, starting out as a one-sided love on Renton's part due to Eureka not understanding human emotions, to co-pilots, to love interests, to husband and wife.

Prior to their meeting, Eureka is sent by Holland (leader of the Gekkostate) to retrieve the Amita Drive from Thurston Garage; it’s creator, Adroc Thurston, had long since been presumed dead and it was in the hands of his father. When she accidentally crashes Nirvash into the garage and upon seeing her for the first time, Adroc’s 14-year-old son, Renton, is immediately speechless and entranced by her beauty. He tries to make a conversation with her as he repairs Nirvash but she is not interested in chatting with him as she is just waiting for the repairs to be completed so she can return to the Gekkostate. However he amuses her when she sets the remains of his room on fire after having destroyed it from the crash and she laughs as he tries to put out the flames. Some members of the Gekkostate, watching from afar, note this is the first time Eureka has ever smiled. After hastily leaving due to a military intervention, he risks his life to reach her and give her the Amita Drive, and clumsily confesses that he loves her, but this confuses her as she doesn’t understand what ‘love’ means. After implanting the Amita Drive into Nirvash and activating the Seven Swells, Eureka finds herself interested in having Renton around Nirvash because his help made her need him to continue helping her. Renton reluctantly agrees to join Gekkostate but is disappointed when he realizes that Eureka sees him as a child, she is confused by his advances, and has three adopted children herself.

Unlike how most of the Gekkostate treated her with respect as the pilot of the Nirvash, Renton instead sought to help her overcome her struggles as much as he could after she confided in him about her past misdeeds and desire to atone them, and he often told her that she can become a better person through the change in her. Overtime, as Renton begins to understand how his role affects Eureka and that of the Nirvash Type ZERO, he vows to protect her. Because of this, Renton's admiration and infatuation towards Eureka later grows into genuine care and affection, allowing him to truly fall in love with her.

However, Eureka was oblivious about what "love" meant and did not reciprocate his feelings. Despite this, she appreciated his companionship and admitted to him on more than one occasion that she found him to be the most interesting person she'd ever met. Originally the two of them were partnered to pilot the Nirvash, with Renton guarding the Amita Drive, but Eureka found herself intrigued by Renton's good nature and shyness. Eureka credits his presence on the Gekko for allowing everyone to have fun and be more open with one another. When Eureka starts to become depressed as she feels her partnership with Nirvash declining, she thought that Renton was somehow responsible for this due to him being to pilot it with more ease, and she became jealous and little bit angry at him. Being too young to understand and lack of communication between the two, Renton failed to see this and and made things worse by exhibiting frustration at her lack of appreciation for him helping her pilot Nirvash.

Their relationship is almost destroyed when Eureka attempts to let the Scrubs absorb her in order for her to end her pain and misery but then decides she wants to live. Renton saves her in time but he is kept away from her by the crew as Holland blames him for the incident. When Eureka rejects him after he tries to explain his feelings, he decides to leave for good. As Eureka recovers, she later reveals that she never held any negative opinions towards him and wanted to tell him about her confusing feelings for him. After learning of his abandonment, she bursts into tears, casted all the blame on herself, and became desperate to see him again. This leads her to realize that she had indeed fallen in love with Renton, and for the first time, she even lashed out at Holland after he said that Renton was not important. She decides to go searching for him, unaware he is returning to protect the Gekkostate from a military attack. After he saves her from being killed, the two reconcile, Eureka declares Renton as her partner and puts all her faith in Renton, and tells him that she can overcome anything as long as she is with him. When Renton learns Eureka is a Coralian, she admits she didn’t tell him sooner because she was afraid he would reject her but he assures her that he wouldn’t reject her because she has always been special to him.

After entering into a relationship, she becomes very devoted to him and takes most things Renton says to heart, and looks to him for help. She becomes determined to make Renton happy with her, seen when she tried to use makeup for the first time to look pretty for him and when she assured him that she would never leave him after he asked her to stay with him forever. Her love for him has also grown so strong to the point where she can't bear being apart from him. Upon learning she is able to bear children like a normal human can, she quickly envisions herself marrying him and having a family with him, which Renton reciprocates. Renton takes on a father role to her adopted children and they come to view themselves as a family. It was because of Renton and Eureka's deep love for each other that they are selected (as a Coralian and a human) to cross the Great Wall and reach the Promised Land which is Earth, save world from the Limit of Questions, and unite the two species via their union. Although both briefly spare over Eureka’s insecurity for not being human and Renton’s frustration that she knew his father a long time ago, they always patch things up.

After successfully passing the Great Wall and reaching Earth, they begin quarreling over how to complete their mission and Eureka withdraws from Renton as her body starts to change. Eureka had doubts over how Renton would react to the changes on her body, but after he discovers the changes, he self-harms to prove he doesn’t care about the changes and Eureka later tends to him as he has a fever. After she transforms further, he later tells her that she was still beautiful. Eureka was overcome with happiness and tells him that she loves him. Later, when Eureka was about to become the next Command Cluster, she apologized to Renton that she can't be with him after all. However, Renton vowed to give up his humanity if it meant being with her and rescued her on his own, promising to be with her forever and they shared their first kiss, allowing them to activate the Second Summer of Love and save the planet. After Nirvash's departure, Renton and Eureka decided to return to Bellforest and raise the children together as a family. A year later, shortly after Renton turned 16, they got married and formally adopted the children.

Shortly after, Renton and Eureka had two children together: a daughter named Amber, who died shortly after birth, and a son named Ao. Renton and Eureka were devastated by the loss of their daughter and continue to mourn her. Ao is very close to his mother while having a complicated relationship with his father but loves him nonetheless. When talking about how she met her husband to their son, Eureka described Renton as immature, a crybaby, and a bit hopeless when they first met, but ended the comment by saying she loved everything about him

Fanon
This ship was immediately popular when the series was released in 2004. Fans compliment the relationship as a string example of true love, where Renton and Eureka benefited each other and made many impossible events occur together. Others consider it unhealthy because of how fast he fell in love with her and how she treated him poorly in the beginning.

Trivia

 * Although Eureka was found the same year Renton was born, as a Coralian, she ages more slowly than a human, and thus will outlive Renton.
 * According to the first light novel book, Renton had dated one girl but never liked any girls other than Eureka.
 * The date of their marriage is April 2, 12006.
 * Their daughter’s name, Amber, is after the amber gemstone (which contained a ring with the first letters of Renton and Eureka’s name inscribed on it) they found on Earth; whereas their son’s name, Ao, means deep blue and can be contributed to the sky or ocean.