With the HUGE cast of characters in 'Heirs', the potential relationships are practically endless. I will need some time to digest what happened in the third episode but let's take a look at the five relationships that caught my attention after the second episode.

SEE ALSO: [Spoilers!] Heirs Ep. 1: The Five Biggest Lies

5. Jung Ji Sook and Han Ki Ae

The Kim household has three mothers to contend with- Won's mother, who is out of the picture, Tan (Lee Min Ho)'s mother Ki Ae (Kim Sung Ryung), who is Mr. Kim (Jung Dong Hwan)'s mistress and has never actually been his wife, and the "second wife" Ji Sook (Park Joon Geum) who raised Won and Tan but has no children of her own. Ji Sook brought Ki Ae into the  Kim household as a threat- Ki Ae is a family secret, so if Mr. Kim tries to cut Ji Sook out of the will, she'll expose his mistress and illegitimate child. A wife and a mistress of the same man under one roof is certainly a recipe for disaster, but the two seem to have some kind of working relationship- they both know what's going on, and they've just accepted it as the way things are. How long before this blows up?

4. Kim Won and Yoon Jae Hoo

Won clearly has big plans and high aspirations for himself within Jeguk Group- that's why he exiled Tan to California and somewhat tolerating the situation with his dad's wife and mistress at home. It's also the reason why the unassuming chief secretary Yoon Jae Hoo (Choi Won Young) is a problem. Jae Hoo doesn't align himself with Won or his father or any one person- he states that he simply works for the company. As a nice guy who tries to do best by everyone, Jae Hoo's in a prime position to get exploited by those in power for their own gains, and I don't think anyone would put it past Won to step on the little guy to get ahead.

3. Kim Tan and Rachel Yoo

Tan and Rachel Yoo (Kim Ji Won) have been engaged for a year. They got engaged when they were seventeen. We've already seen that Tan is not at all interested in this marriage- in episode 2, he flat-out reveals that he has no plans to marry Rachel and that he only got engaged to her so he could avoid marrying her. Rachel is on a completely different page with this situation- she wants to marry him, she expects him to act like a proper fiance, and she's very upset that he's not interested. However, we're not quite clear why she's so intent on marrying Tan- maybe it's because she genuinely thinks she's in love with Mr. Too-Lazy-To-Do-Anything, or maybe it's just because she's so desperate to get away from her overbearing mother (Yoon Son Ha) and to avoid getting caught up in Young Do (Kim Woo Bin)'s family drama. 

This is especially interesting since Rachel's mother seems to think that Tan and Young Do are close friends and that they should be excited that they'll be step-brother-in-laws after all the marriages take place (Rachel and Tan, Rachel's mom and Young Do's dad (Choi Jin Ho) ), when it's clear that the two aren't even speaking. Furthermore, Rachel is refusing to tell Tan about her and Young Do becoming step-siblings- what plans could she possibly have up her sleeve?

2. Kim Tan and Cha Eun Sang

How could I write a list of interesting relationships without mentioning our star couple? Almost everyone in this drama has some kind of history and baggage with each other, but we see Tan and Eun Sang (Park Shin Hye)'s first meeting. The fact that her best friend's father is, as I mentioned before, likely to get squished by Tan's older brother, makes for some interesting potential future drama. We already know that Eun Sang's mother (Park Hee Nam) is a housekeeper in Tan's family's home and has helped Tan's mother cover up her indiscretions (the wine in episode one), so there's definitely some heavy personal baggage coming into the relationship that the two of them simply can't avoid.

Tan's confession in episode 2 is obviously spurred on by the sense that they don't have much time- he's engaged to Rachel, Eun Sang is in the process of trying to get back to Korea while he stays in California. There's the added adrenaline rush of having just barely outran some thugs who want something from Tan. As an audience, we all know that Tan and Eun Sang have at least another 18 episodes to figure things out, and putting the confession this early in the drama is obviously going to be more of an obstacle than a step forward for our main couple.

1. Choi Young Do and Lee Hyo Shin

Young Do and Hyo Shin (Kang Ha Neul!!!) takes first place because it was the relationship that took me completely by surprise. Not only did I not see it coming, but I don't understand where it's going and I am really curious to see how it plays out. At first it looked like Young Do was out to get Hyo Shin (the thing with the water sure seemed like an underhanded threat of some kind), and then it seemed like Hyo Shin had blackmail on Young Do, but in an instant, the atmosphere between the two switched to some kind of fondness or friendship, with no explanation for the change or why this back-and-forth seems to be normal for them.

It also helps that Kang Ha Neul plays Hyo Shin- he was a scene-stealer in both 'To the Beautiful You' and 'Monstar' and one of the few actors to get me to stick with those dramas in spite of the absolute ridiculousness of the stories. I've been waiting for him to finally get a bigger role in a drama, and hopefully Hyo Shin is a step in that direction for one of my favorite up-and-coming actors.

Of course, these are just five interesting relationships- there are plenty more that we didn't even touch- how about Eun Sang and her mother, whom she loves but is also kind of ashamed of? Or Won and Tan and their father and all that family tension? Or Bo Na (f(x)'s Krystal) and Chan Young (CNBLUE's Minhyuk) and how/why he deals with her dramatics? Catch episode 2 of 'Heirs' at Drama Fever and tell us what you think of all the complicated relationships in the comments!