Superboy (also known as Conner Kent and Kon-El) is a clone of Superman and one of the founding members of the Team in Young Justice. He is also the main love interest of Miss Martian.
Superboy is the 16 week old hybrid clone of Superman and Lex Luthor, though physiologically he is 16 years old. Because of Lex's human DNA, Superboy is not as powerful as Superman, but his human DNA keeps him from becoming a feral monster like his older sibling. When he is first introduced he attacks the group but after they escape and joins the team.
Superboy and Miss Martian first met each other when the newly formed team discovered that Miss Martian would be joining them. They soon befriended each other and Miss Martian quickly developed romantic feelings for him upon their first meeting. However, they soon got off to a rocky start when Miss Martian used her powers to telepathically speak to Superboy, trying to comfort him as he didn't have a real name, but Superboy lashed out at her as because of his experience at Cadmus, he developed a hatred for telepathy. However, he quickly came to regret how he acted, but didn't know how to apologize, but after some advice from Aqualad, Superboy eventually managed to apologize to Miss Martian. While at first Superboy didn't show his emotions, he soon started to develop romantic feelings for Miss Martian and as time passed, their romantic feelings for one another grew stronger, but both were too nervous to confess how they really felt.
While Miss Martian and Superboy kept their feelings hidden from one another, they soon came to realize they had competition from others members of the Team, mainly Kid Flash and Artemis as they both had feelings for Miss Martian and Superboy respectively. However, neither Miss Martian nor Superboy showed any interest and as they had more experiences together through their missions, they grew more closer and their feelings grew more and more stronger. There are several episodes that also heavily focus on their growing relationship such as Bereft, where Miss Martian restores Superboy's memories when they and the rest of the Team were attacked by the psychic villain, Psimon. Together, they managed to defeat Psimon and almost shared their first kiss until Sphere had arrived and interrupted them. Miss Martian and Superboy also attended the same High School together and Miss Martian finally gave Superboy his name, Conner Kent.
Eventually, Miss Martian and Superboy finally became a couple in the episode, Terrors, where they went undercover as the Terror Twins in the prison, Belle Reve. Superboy had finally and fully come to terms with his feelings for her as he became extremely worried when he wasn't able to get in contact with her. He was determined to find and rescue her and was completely distraught when he discovered her to be frozen in ice. Miss Martian managed to free herself and reunited with Superboy and they quickly shared their first kiss, thus finally becoming a couple.
However, they both decided to keep their newly formed relationship a secret from the rest of the team, but everyone slowly began to find out and even their mentors discovered their relationship. Since becoming a couple, Superboy is shown to worry about Miss Martian's safety several times such as when she was almost killed by Red Tornado's siblings, Red's Torpedo and Inferno. However, Miss Martian was shown to be annoyed by his protectiveness on one occasion, but they soon worked out the issue. Later, during a supposed invasion of Earth in the episode Failsafe, M'gann had confessed to Connor that she loves him and became devastated when he was "killed" by the aliens that she fell to her knees.
However, their relationship was almost threatened as both Lex Luther and Queen Bee tried to use both Superboy and Miss Martian. Lex Luthor had tempted Superboy with special patches that allowed him to have all the powers of Superman temporarily, but would also cause his anger to increase, leading to some clashes with his teammates. Queen Bee had blackmailed Miss Martian, threatening to reveal her true appearance as a White Martian which would possibly lead her friends and Conner to abandon and hate her.
Eventually in the episode, Usual Suspects , they both revealed their secrets. Superboy was the first to reveal the patches, including the discovery of Lex Luthor being his human father and Artemis had revealed to the team the truth about her family. Miss Martian gathered her courage and faced her fears and finally revealed Queen Bee blackmailing her and finally showed them her true form. However, Superboy's feelings for her don't change, revealing he already knew when she restored his memories in Bereft and decided to wait until she was ready to tell him herself, showing he truly loved her and thus their relationship became even more closer and serious. Later, when they and the rest of the team had saved the Justice League and it was time to celebrate New Year's, Miss Martian and Superboy shared a romantic kiss along with several members of the Team such as Kid Flash and Artemis and Robin and Zatanna.
In the second season, taking place five years after the first season, Superboy and Miss Martian are revealed to have recently ended their relationship and Miss Martian has started dating Lagoon Boy, another member of the team. Superboy is soon revealed to be upset about her relationship with Lagoon Boy, showing obvious signs of jealously and anger, but admits that while Lagoon Boy can be a jerk, he does treat Miss Martian well. However, it's later revealed that Superboy broke up with Miss Martian, partially because he didn't outwardly age, but mainly because he was upset on how she abusing her telepathic abilities as whenever she probed the minds of their enemies, she would leave them in a catatonic state.
Aside from Miss Martian misusing her powers, Superboy ended their relationship as she attempted to erase his memory of their argument on how she was using her powers. Due to this, Superboy was greatly hurt and devastated while feeling immensely betrayed by her actions, leaving him no choice but to officially end their relationship. However, despite their issues, Superboy and Miss Martian still harbour strong feelings for each other, showing that they obviously still in love, but don't want to admit it. Miss Martian was also revealed to still feel great remorse and guilt for her actions toward Superboy and continuously apologized whenever the subject was brought up. Superboy also revealed his beliefs that Miss Martian didn't truly have any real feelings for Lagoon Boy, believing he was only her rebound boyfriend, despite Miss Martian's protests.
It's also shown that several people, mainly Beast Boy and alien girl, Alanna supported the two reconciling as Beast Boy attempted to remind the pair of the happier times they shared when they still together and Alanna pointed out that Miss Martian obviously still loves him after learning about their romance. However, their relationship still continued to be strained for quite sometime, but both showed to still care and worry for one another such as when Miss Martian felt guilty for not throwing a party for Superboy on his birthday or when Conner tried to comfort M'gann after the death of Artemis.
Later, during a mission to rescue several teammates who were captured, Miss Martian confronted Aqualad and used her powers and telepathically attacked him as revenge for killing Artemis, leaving him catatonic. However, she soon realized her grave mistake as she realized the truth that Aqualad and Artemis were on a deep undercover mission to infiltrate the Light and Reach. Due to the event, Miss Martian felt an immense guilt for what she had done and became afraid to even use her powers, coming to realize that Superboy was right along on how she was wrongly using them.
Due the revelation, Miss Martian began avoiding Lagoon Boy and she began to rethink certain issues and decisions, including her relationship with La'gaan. Eventually, she breaks up with Lagoon Boy, realizing he was only ever her rebound boyfriend and that she was being selfish as she was only with him because he made her feel better about herself. Miss Martian also finally came to realize that she was still in love with Superboy and attempted to reconcile and renew their relationship, but became upset to learn he was currently spending time with their friend, Wendy Harris and believed they started dating. Later, Miss Martian apologized to Superboy, admitting that it was all her fault that their relationship ended and revealed her awareness that Connor started dating Wendy. However, Superboy assures her that he was actually helping Wendy with her relationship with another friend Marvin, leaving Miss Martian delighted upon hearing the news. By the end of the second season, Miss Martian and Superboy are shown to have decided to renew their relationship.
Bekka|Big Barda|Black Canary|Joker|Hawkgirl|Mera (Aquaman)|Sapphire Stagg|Steve Trevor|Superboy (Young Justice)|Terra|Zatanna Zatara