As a child in middle school, Lyra grew feelings for her best friend's brother, Shon. Shon eventually tells her that he reciprocates her feelings - not yet knowing that they are reciprocated - after Lyra gets injured and they start dating. Shon is one of Lyra's most important friends (and new boyfriend), and he works with her at the store she owns called Carnation. He is very protective of her, especially regarding things that involve Ian.
In Season 2, Lyra became heartbroken when she learned that Shon had kissed her to take up the curse and save her. She has promised to find some way to bring back the Shon that she loves. Even as a siren, Shon's heart glows green. The green heart is a remnant of the old Shon inside him that he's forgotten. Lyra and Shon split the curse, later on, bringing Lyra back to the state she was in, in season 1, and allowing her to find the old Shon in her dreams.
Ian is the siren who kissed Lyra underwater after an event that left her heartbroken over Shon. Lyra gives him the name of Ian after her deceased pet goldfish (among other things), but hides this fact by only referring to it as a 'masculine and popular' choice. Due to a mishap during the exchange of a siren's heart for a human's in Season 1, Lyra and Ian possessed traits of both species. They decided to work together to find out more about this unusual situation.
At the start of Season 2, it is shown that Ian has some form of feelings for her, with his heart being broken upon seeing her kiss Shon. At the end of episode 88, he talks to her, then says, "I'm only selfish enough to do this;" thereby proceeding to kiss her. In the next episode, Lyra's reaction is shown to be tired and somewhat upset. Even so, she cares for Ian throughout the series.
Kori is Lyra's best friend from childhood and both of them have always stuck up for one another. Over the years growing up, they told each other everything. This includes Lyra's crush on Kori's brother, Shon, as seen in Ep. 1 of the series. They have an opposite kind of relationship, Kori being energetic, loud, and dramatic and Lyra being shy and quiet.
Kori affectionately nicknames Lyra as "Lyly."
Although Lyra talks about her often, it was uncertain whether or not she was alive until Ep. 26. Hona may have had a significant other at one point in her life, but has never mentioned this to Lyra. Instead, she looks away solemnly whenever Lyra asks her about it.
At the beginning of episode 88, it is hinted that Hona knows about sirens and the curse, but after thinking about Lyra for a while, she says, "No...no, it can't be. She should be safe from that." Later on, however, this is confirmed to be true when Hona helps Pele adjust to her new reality as an ex-siren. She then hints that there was somebody siren she once knew. in the second season it is also revealed that Hona is the sister of the Poseidon and is the real reason for her sister Aleah becoming the Poseidon in the first place.
Aleah sees lyra as rival thinking that Lyra is her sister, the one the ruined her life. This was mainly because Aleah had been Shon's girlfriend, but they later broke up when Lyra and Shon found out their feelings were mutual despite the fact that she was gonna use him as her source of immortality. She was Ian's target to help turn him and Lyra back into humans, but Lyra didn't want Ian to do this unless she said to herself that she wanted a new life.
Lyra attempted to become friends with Aleah by asking her to go out shopping with her sometime, but Aleah declined. Later on, it's revealed that Aleah is the Poseidon and may potentially be Lyra's aunt which is Aleah's real sister.
Although Lyra and Emila never formally met, a flashback from Hona's perspective demonstrates that Emila is indeed her birth mother despite the fact that she never wanted to have a baby. At the time of Lyra's birth, Emila was a siren; causing the latter to turn into sea foam after bringing her child into the world as she didn't have the ability to do so naturally. Unfortunately, this caused Emila to die before meeting her newborn daughter. She also spent a lot of time around kai or who we now know as Ian when she was married to her somewhat abusive husband.