Seiun Sky is a playable character from "Umamusume: Pretty Derby". She is depicted as a laid-back and carefree individual, who takes life as it comes. Tortoise and the hare and all that, you know?
She often tries to slack off from training, but makes up for it in her own ways. After all, she cares more than she lets on. You have to be careful around her, as she analyses her opponents frequently and is not afraid to exploit their weaknesses during the race. Thus, she is known as the Trickster.
Despite this, she does not do anything morally incorrect or anything that breaks official rules ("What? I'm not going to do anything... Anything bad, that is!"). This shows that though she seems otherwise, she truly does listen. As such, her 'complaints' about her friends calling her Ligne Droite outfit cool in the homescreen are nothing but a bunch of lies. Throughout her story, career, and other scenes she is featured in, you can see she is the kind of person who only pretends not to care.
Another quirk of hers is she likes to fish before a race. A big catch can only mean a good thing! So she is often late to races in Career.
Sei is... Complex.
She can win any race she puts her mind to, she is just in the endless cycle of slacking off. She pretends she has no expectations for herself to the point where it manifests into reality. I'm pretty sure she gets the slacker negative effect more than any other Uma.
She runs off when trainer asks her about Nishino Flower because if she pretends to be nonchalant it will go away. "Do you have someone you race for" Flashback to Nishino Flower giving her a flower crown. "NO I DO NOT"
Ligne Droite's homescreen idle complaining about Spe and her friends saying she looked really cool. I know you liked that. Ligne Droite flirting with Fuji then running away saying it was a joke. You meant that, with how warmly you referred to her in monologues after that.
Anime: she's been nonchalant so far but when she loses against Spe, she is putting 100% into still looking put together, because her expression remains nonchalant but her internal monologue is frustrated. I think she has a fear of looking weak alongside a fear of losing.
I think it's cause as she's labelled the "Trickster", she is used to exploiting other people's weakness when they least expect it, but whenever someone tries to ask her about something serious or emotional, she will cramp up. I will exploit your weakness but you cannot exploit mine, I think is her thought process.
She can't lose, and she can't show fear of losing. So then, why even try?
In real life, Seiun Sky was never an appreciated horse. His genetics were not wanted, and he wasn't exactly the best of the best. Umamusume: Pretty Derby! gives all of these racehorses a second chance. This time, Sei can win the races she wants to win, climb higher than her real life counterpart ever could because she isn't really physically limited anymore. However, this time, the thing holding her back is herself.
She knows she has the potential to win this time. She has as much drive as every other Uma, however, she is afraid of failure. She can win easily, but in trying to persuade others that she is an easy opponent, she has convinced herself too (My belief, at least — and I can attest to this because. "She's just like me frfr"), and is now afraid of losing, because her dreams mean more to her than she lets on.
After all... Why even try if I'm going to lose, right?
After winning the Takarazuka Kinen in Career, she loses her will to race. She doesn't want to let down everyone by losing. She believes she has reached the peak of her abilities while everyone else continues to surpass her. She has the drive, yes, but she stops herself before even trying. This concerns King Halo, who asks her why can't she just say something useless like usual?! This shows even her close friends know how Sei works.
The trainer jumps into the water to catch a fish with their own two hands, after she had struggled to land a catch for hours, to teach her a lesson. I don't quite recall this part of the story, but I believe the lesson was... All the tricks don't matter if you don't even try, and if you try, you can succeed without all those strategies! And I know you can do it. Because I believe in you! ...Well. That was at least what I was thinking during the career, cheering her on. I love her sooo much.
To quote Silence Suzuka's chapter in the main story, Umas race with the hopes and dreams of everyone on their backs. That is why they race, and with the trainer showing their belief in her, and how far they were willing to go (jumping into the water) for her, I think that's also why she was able to get back on track.
She regains her drive, and in the good ending of the career, trainer reads her a newspaper clipping. An Uma who may be the best of the century. This reactivates Sei's competitive streak, and she tries to put on a nonchalant air, but you can see that she really is excited to compete again. She is just like every other Uma, but she doesn't show it.
So she does get a second chance. But the hurdle she has to overcome is herself, and who knows if she actually does it, as careers and character stories often feel like alternate timelines to me, like how the anime is pretty different to the in game main story.
**Important Note: I also think she KNOWS she has convinced herself that she will lose, and I think she KNOWS she can win. So when she really tries in her races, she REALLY tries with them.
If Sei was a Hamilton song she'd be Wait for it and Satisfied, and if she was a Hamilton character, she'd be Burr.
At first, this may seem absurd. But let me explain myself. First, I will explain why I think she is Wait for it and Satisfied in particular. I assume you have knowledge of the musical 'Hamilton' for this section.
Wait for it is self explanatory, Sei is a front runner. She uses more stamina than other front runners to reach the front, and maintain the lead. But when she loses, she has to watch the other runners overtake her while all she can do is fall behind. She has run out of stamina. It's how Burr feels when he sees Hamilton achieve so many things: he can only wait for it, because it is all he has ever done. But he knows that good things come to those who wait (One of Sei's quotes, I think!) and it almost feels like he has a trick up his sleeve. After all that waiting he will make a move. You could say this is more befitting of a late surger, but Sei is the Trickster, and Seiun Sky [Reeling in the Big One]'s unique is "Angling and Scheming". Could you not say Burr is Angling and Scheming?
"I am not standing still, I'm lying in wait" — Slightly accelerate on the final corner. Or... "Angling and Scheming"!
"I’m not falling behind or running late" — Falling behind? No. I am just biding my time, analysing my opponents... Lies. You are just afraid of making a move.
"I am the one thing in life I can control" — Sei not racing because if she doesn't she doesn't lose
Satisfied is not that obvious. Angelica will never be satisfied, she wants Hamilton as much as Eliza but for the benefit of her sister she puts her feelings aside. It's similar to how Sei will never be satisfied with how many wins she gets like many other races, but hides it under a layer of pretence (Partially to trick others, see Wait for it but still, she feels frustration because she feels like she has reached the peak of her abilities while others are still climbing. She doesn't willingly show weakness as I mention in Chapter 2). Spe bursts into tears at a loss and outwardly shows determination to reach the top, and Sei feels the same. She wants to win the race as much as her but she hides it, like how Angelica hides her feelings. This perhaps isn't the strongest argument, but I hope the meaning of my words is understood.
Unrelated lyric, in Non-Stop Burr asks, "How do you write like you're running out of time?". You can also see this as Sei when she first lost to Spe in the anime, "How do you run like you're running out of time?"
"I’m taking my time / Watching the / Afterbirth of a nation / Watching the tension grow." — Sei at the end of her career, though her competitive streak soon reactivates.
Because they're really cute. And so is she.