These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Sakura Gari
Complete Monster - Dr. Katsuragi, the Saiki clan's doctor and one of Souma's lovers. Not only is he a disgusting pedophile and a Domestic Abuser, he drugs, rapes, and tortures Masataka (this includes whipping him, sticking a household object up his anus right after raping him, and holding his hand in boiling hot tea because of his jealousy over Masataka being the one Souma loves, when he loves Souma to an insane degree himself). Oh, and because Souma hated his stepmother Sakurako for raping him when he was younger, Katsuragi takes his words literally and forces a reluctant, young Souma to kill her. He took Souma's hand, which held a knife, and forcibly made him cut Sakurako's wrists, effectively killing her, while she was naked and passed out in the bathtub. And after the act, he also practically rapes Souma. Not only was Souma left traumatised by the deal, but this also contributed to Souma's "half-sister" Youya going from a simply adorable toddler into a scary Yandere and Creepy Child that calls himself "Sakurako", having walked into his mother's murder and gone mad from the horrifying sight. When Souma confronts Katsuragi on his rape and torture of Masataka, Katsuragi denies the accusation and tries to seduce Souma. He acts uninterested and mentions Masataka's name, so Katsuragi actually grabs Souma by the throat and tries to strangle him. Fortunately, though, Souma isn't fazed and deals him a huge Humiliation Conga. Which Asayo transforms into a Karmic Death.
Also, Sakurako's mother
Interestingly, Souma is a subverted and deconstructed form of this trope. He initially seems like a Complete Monster, at least to Masataka (who calls him out on it with a What the Hell, Hero?), when he tells him that he's responsible for all the deaths surrounding him, saying he effectively drove all his former lovers to suicide, shows no remorse for it, and says that he seduces and sleeps with anyone because he wants it. The truth is a lot dirtier and uglier. And that's before we get to the torture.
You can make a very strong case for Katou, too. he actively helped break his own child, Youya, into little pieces, turning the boy into a borderline Complete Monster in his own right by keeping up his lover's poisonous Mind Screw of him (see above) and enabled the abuse of Souma by keeping quiet of all the crap he knew the kid was going though in an attempt to have his own son take over a family he didn't really belong to via murder and other tactics — all while coming across as a Ol Rentainer, nothing more. (Contrast with Ohatsu, who also kept quiet about Souma's abuse but was wrecked with guilt afterwards and broke down crying when she explained it to Masataka.) Charming: and, unlike others, we get no hint of a Freudian Excuse for this... and he walks off into the sunset in full Karma Houdini-mode at the end.
Draco in Leather Pants - Yes, Souma has a heartbreaking and terrible past. Yes, he's no Complete Monster. But he did sexually abuse the first person in a long time that gave him real affection, and no Dark and Troubled Past justifies or handwaves that. Even Souma himself deeply regrets what he did to Masataka, fandom!
Ho Yay - In addition to the obvious Yaoi relationships, there's a lot of hints that some side characters are attracted to Souma.
Considering that it's Souma, odds are they've slept with him already.
Jerkass Woobie: Souma and Sakurako. Both have heartbreaking pasts and big reasons to be the way they are, but it's NOT a justification for the shit they pull on others.
Magnificent Bastard - Souma has traces of this, specially when he brilliantly and spectacularly punishes Katsuragi.
Oh God, Masataka's torture and rape, and let's not go into Souma's childhood.
The numerous times Masataka and Souma attempt suicide and how Sakurako successfully manages to commit suicide in chapter 9, slitting her wrists open (apparently with the family's katana) and then drowning herself in a nearby pond.
Tear Jerker: The whole story is a Tear Jerker, but what takes the cake is Sakurako's Villainous Breakdown, in which among other things, she lashes out at her father while crying and screaming "Answer me father! Why was I born?", as well as her suicide.
Asayo Katsuragi appears in only three scenes, but she's a walking Tear Jerker. In the third one, though, she's become a Yandere... and earns a CMOA by setting Katsuragi on fire as punishment for his acuse.
The Woobie - Poor Masataka. And Asayo, Katsuragi's wife. And the young maid that was Souma's mistress and got pregnant with his baby, then was tortured by Sakurako, lost her baby and ended up horribly broken.