MAJOR SPOILERS ahead for Love Alarm season 1.

Netflix's Love Alarm season 1 ending is a cliffhanger; we break down what Love Alarm 2.0 is and what it means for Kim Jojo (Kim So-hyun). Based on the Love Alarm webtoon created by Chon Kye-young, season 1 of the K-drama (Korean drama) introduces Jojo and two boys who are both interested in her: the former model and new kid at her high school Hwang Sun-oh (Song Kang) and his childhood best friend Lee Hye-yeong (Jung Ga-ram). Their love triangle is made all the more complicated by the incredibly popular mobile app Love Alarm, which allows users to know who within a 10 meter radius has romantic feelings for them - and alerts those they have romantic feelings for. Since the app syncs with the user's heart, it's impossible to hide your feelings.

This causes some trouble for Jojo when she's in high school because, while both Sun-oh and Hye-yeong are interested in her, the latter gives her up for his friend when he sees Jojo ring Sun-oh's Love Alarm. Still, Hye-yeong accidentally rings Jojo's Love Alarm and he ends up deleting the app. But though Jojo and Sun-oh are in a relationship, she grows increasingly insecure, confiding in her unpopular classmate Cheong Duk Gu (Lee Jae-eung). He gives her a unique shield for her Love Alarm that makes it so she can't ring anyone's alarm, but the shield can only be removed by the app's developer. Jojo uses the shield to break up with Sun-oh, convincing him she no longer has feelings for him. Four years later, Jojo runs across Sun-oh and Hye-yeong again by accident. Both still have feelings for her, but while Hye-yeong tries courting her without Love Alarm, Sun-oh is resentful of how she dumped him.

Related: What To Expect From Love Alarm Season 2

The Love Alarm season 1 finale revolves around the Love Alarm 2.0 presentation, where a new feature is unveiled and the long mysterious developer is unmasked. Jojo decides to track down the developer of the app and get the shield removed from her Love Alarm so that she can pursue a romantic relationship in which she's open about her feelings. While attending the Love Alarm 2.0 presentation, she runs across both Hye-yeong and Sun-oh - and his new girlfriend Yook-ji (Kim Si-eun), for whom he doesn't ring her Love Alarm. Both men ring her Love Alarm, but she's unable to ring either of theirs. Now, we dive into what this ending means for Jojo and a potential Love Alarm season 2.

Love Alarm's Developer Revealed

Kim Si-eun and Song Kang in Love Alarm season 1

At the start of the Love Alarm 2.0 presentation, a woman named Lee Seon-yeong, the CSO of Love Alarm's C&C department, reveals the developer of the app to be someone named Brian Chon. Now, this goes against everything Love Alarm has hinted at in the episodes leading up to the finale. Though never explicitly stated, it's made clear to the viewer that Duk Gu is the developer of Love Alarm. In the first episode, he's shown looking up at the sky before the Love Alarm logo appears in the clouds. He also gives Jojo the one-of-a-kind shield tech for her Love Alarm. But the biggest proof Duk Gu is the developer of Love Alarm is that he's shown in the developer's bedroom, shutting down the computers before jumping out the window. It's this same bedroom that the finale cuts to as Seon-yeong introduces Brian Chon, describing the developer as a shy high school boy.

It's possible that Duk Gu reinvented himself after, as Jojo describes in an earlier episode in voiceover, he disappears without a trace, becoming Brian Chon in order to distance himself from his embarrassing high school experiences. After all, he gets his heart broken by Jojo's cousin Park Gul-mi (Go Min-si), which is how he becomes friends with Jojo and why he gives her the shield. It's possible Brian Chon is Duk Gu, since the director of the series, Lee Na-jung, makes a point of hiding the developer's face in shadow throughout the entire presentation. However, it's much more likely that hiding whether Brian is Duk Gu is setting up for a twist in season 2. Perhaps Brian Chon is not actually the real developer of Love Alarm, he's simply someone chosen to pose as the developer. But if that's the case, the question becomes what happened to the real developer, Duk Gu, and why he wasn't publicly revealed as the creator of Love Alarm.

What Happened To Duk Gu?

Lee Jae-eung as Cheong Duk Gu in Love Alarm season 1

There's another key character in the Love Alarm season 1 finale whose identity remains shrouded in mystery, even after the episode ends: the man in the Anti-Love Alarm van. In the four years since Love Alarm launched, it's changed the world, specifically regarding how people confess their feelings for one another. Love Alarm is so integral to Korean culture that there are movies about it, self-help books to get more people to ring your Love Alarm, and it's even become part of wedding ceremonies. But there's a dark side to it, as we see when a group of Koreans who've never had their Love Alarm rung die by suicide in a public park. There's also an Anti-Love Alarm movement that protests the app, and this group shows up to protest outside the Love Alarm 2.0 presentation.

One member of the Anti-Love Alarm movement remains in a van, speaking into a microphone that projects over speakers. Though we only see his lips, they bear a resemblance to Duk Gu. We know Duk Gu didn't die by suicide, even though that's implied in the scene when he disappears. Remember, that story is told from Jojo's perspective and she may have assumed he died by suicide given what he'd gone through. However, if that were actually the case, she'd have said that, rather than say he disappeared.

As for how Duk Gu becomes a member of the Anti-Love Alarm movement, it makes sense for him to grow to hate his own creation, considering the heartbreak it brought him. Gul-mi never returned his feelings, and continually humiliated him after he rang her Love Alarm because it embarrassed her. Considering he also created the shield tech for Jojo, it's not a stretch to see how he might instead put his efforts behind protesting the app he created - especially when it's become so ingratiated in Korean society. (It's also likely Duk Gu is one of the viewers of Gul-mi's webcast and sees how unhappy wanting to get into the Love Alarm Badge Club has made her, prompting him to further resent the app.) However, Duk Gu not being revealed as the real developer of Love Alarm has serious implications for season 2, particularly the viability of Love Alarm 2.0's new feature.

Love Alarm 2.0's New Feature Sets Up Season 2

Song Kang and Jung Go-ram in Love Alarm season 1

Since Duk Gu isn't introduced as the developer of Love Alarm at the 2.0 presentation and he's instead leading a protest outside, we can presume he doesn't have anything to do with the new feature and hasn't had anything to do with the app for some time. It's likely he abandoned it just before he disappeared, which is hinted at in that scene when he turns the computers off. It's not yet known who took control of Love Alarm after Duk Gu disappeared, but since he's not involved in 2.0, it's unclear whether it will work as well as Love Alarm. After all, there's a little bit of unexplained science in Love Alarm regarding how the app syncs with a person's heart to tell without a doubt how they feel about someone else. The 2.0 feature is instead based on data that Love Alarm collected in its first four years.

As explained by Brian Chon, Love Alarm 2.0's new feature is "the person you will fall in love with." Specifically, it "will now be able to accurately predict how one’s feelings will develop. It’ll be able to tell you who will ring whose Love Alarm, and who won’t ring whose Love Alarm." So, essentially Love Alarm 2.0 uses data to predict how a person's feelings for someone else will develop, whether or not they'll fall in love with someone. This sets up Love Alarm season 2 in two key ways. First, it's unclear how effective this new feature is. Duk Gu wasn't involved in creating it, and rather than being based on whatever infallible method he created for the app to determine the user's feelings, it's based on data that predicts feelings, but predictions can be wrong.

Secondly, Love Alarm 2.0 could directly impact Jojo's relationships with Sun-oh and Hye-yeong. She may even use the new feature to choose between the two men. But if, like we suspect, Love Alarm 2.0 can be wrong, then Jojo may end up with the wrong man because of the app's fallacy. However, it may not be Jojo who uses Love Alarm 2.0. The new feature could also directly impact Sun-oh's relationship with Yook-ji, since 2.0 would finally be able to tell her whether Sun-oh will ever ring her Love Alarm. Or, Hye-yeong could use it to determine whether Jojo will ever love him - though that seems unlikely considering he's one of the few characters determined to live without Love Alarm's influence. There are many ways the Love Alarm 2.0 new feature could impact the romantic storylines in Love Alarm, especially when it's unclear just how accurate it really is.

Who Will Jojo End Up With?

Kim So-hyun as Kim Jojo in Love Alarm

Ultimately, though, Love Alarm 2.0's new feature and whether it can be trusted serves the main throughline of Love Alarm: Who Jojo will choose in the end. From the start, it's made clear that both Sun-oh and Hye-yeong have feelings for Jojo. At first, they determine to let Jojo choose between them, using her Love Alarm as the deciding factor. But when Jojo rings Sun-oh's Love Alarm, Hye-yeong bows out. Although we later see Hye-yeong accidentally ring Jojo's Love Alarm and hide it from Sun-oh, we don't see Jojo ring Hye-yeong's. Even four years later, viewers don't know how Jojo feels about him as he's courting her, though he repeatedly rings her Love Alarm after re-downloading the app. It's possible she develops feelings for him when they're adults, but it's likely she didn't have any romantic feelings for him when they were in high school because she didn't seem to know who he was prior to him ringing her Love Alarm.

But that still leaves Sun-oh. We know Jojo loved him when they were together in high school and it was her fear of her feelings that caused her to download the shield for her Love Alarm and break up with Sun-oh. Although we don't know whether Jojo would still ring Sun-oh's Love Alarm four years later because of the shield, he's convinced she still has feelings for him - and never stopped. Just like he never stopped having feelings for her and continues to ring her Love Alarm despite having a new girlfriend and resenting Jojo.

In the Love Alarm season 1 finale, Jojo is determined not to hide from her feelings anymore and get the shield removed from her app. It would be easy if Jojo only rang the Love Alarm of either Sun-oh or Hye-yeong, but that doesn't fall in line with the themes of the series thus far. Love Alarm explores the very complicated emotions that the app attempts to simplify, with conflict arising when the messy feelings of people intersect with the cold logic of Love Alarm - like when Jang-go (Z.Hera) rings Il-sik's (Shin Seung-ho) Love Alarm when he's still dating Jojo or when the app outs a gay student. The message of Love Alarm seems to be that technology can only help humans so much, but they shouldn't necessarily rely on it blindly.

As such, it seems likely that whoever Jojo ends up with won't be solely determined by Love Alarm or the Love Alarm 2.0 new feature. Instead, she'll have to sort through her feelings and make the decision on her own. Because human emotion is much less predictable than technology and data would have us believe, it's truly a tossup of whether Jojo will choose Sun-oh or Hye-yeong. In fact, she may ring both their alarms if the shield is ever removed from her Love Alarm. Fans will just have to tune in to Netflix's Love Alarm season 2 to find out.

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