That was a semi-big plot point, he didn't. That's why he freaked out and hit the prosecutors car so he would be charged with destruction of private property, something you'll 100% get in trouble for.
So, the unfortunate reality is that South Korea has some really strict laws surround assault and self-defense. If the person defending themselves injures their attacker beyond what a court deems appropriate, or injures their attacker more than the attacker injured them, then the victim can also face jail time. Lots of Korean people are reluctant to ever help out other people in distress because they're afraid of being arrested for harming the attacker. It's actually a really big problem over there. Koreans are taught that they should only mind their own business and not interfere with other people. I lived there for some years and saw many things and learned about these laws.
That applies on this side of the ocean as well, self defense CAN land you on trouble. People can get a gun license and hace a gun nearby, but rarely ever take it out even for self defense (not American, idk what their views are over there). Besides that there were comments on how the special genders were RECENTLY being less discriminated against and some instances on what stereotypes they carry. The own court can be biased, a lot of shitty coincidences happen even if you are in the right.
Besides, he got in jail due to property damage, it was actually mentioned very early on (prologue?), even before the assault happened on the restaurant.
I can understand your points, and generally this work has a lot of wack shit going on, but it's actually quite accurate how they're going about this in terms of South Korean self defense laws, and the fact that they addressed exactly what you said. Others already pointed this out, but just incase it's not clear;
He attacked the Prosecutors car to get himself in prison because his charge for self defense was suspension, not prison time.
South Korean law when it comes to many social issues, such as self defense, is very recessive. Unlike the US, defending yourself with "unreasonable force" can be seen as a crime. Such rules like:
"Be less violent: Your defense should not be more violent than the attack.
Don't use a weapon: You should not use a weapon in self-defense.
Limit damage: The other person's injuries should not require more than three weeks of treatment."
Also regarding the fact it was two Alphas about to sexually assault an Omega- it would be very typical for South Korea to put more blame on the victim of sexual assault if they did something like stab the assailants. The sexual crime issues of South Korea are so utterly horrendous, such cases as the "Nth Rooms" prove such.
Not a U.S supporter by any means, we have just as many if not more problems, but yeah. Overall if he had been imprisoned for the self defense alone, it would have not been that unrealistic...
I 'm sorry I get you can have unrealistic plots but why would he get put in prison for self defense if they were tryna kidnap him? and even if it's shitty there's usually a power imbalance inbetween omegas and betas/alphas so that would also be taken into account in court I can't stand this like I would've read if it was more believable. idk might just be me but like my braincells are tryna putting two and two together and it don't fit and I can't focus on the plot knowing that in the back of my mind