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: Tenjho Tenge
Complete Monster: Sohaku is a power-hungry sociopath who delights in ruining people's lives. Two of his favorite pastimes are engaging in Cold-Blooded Torture and watching one of his subordinates Mind Control helpless victims into fighting and killing each other. He has spent hundreds of years spreading his influence in order to manipulate, use, or kill hundreds of powerful martial artists as well as all the people around them. A few years before the beginning of the story, he experimented on his wife, using her Power Parasite abilities to steal the abilities (and in most cases, lives) of the most powerful martial artists in japan, before judging her too weak, cutting off her arm, and ripping out her eye (which contained the powers she had collected) and giving it to his dragon. Flash forward to the present, and he sets his full plan into motion, indirectly Mind Raping his son, who has the same powers as his ex-wife, into letting his powers turn him into a god-like being whose only purpose is to go on a rampage, killing any powerful martial artists it comes across and stealing their powers. Once this happens, his son goes around the world, killing thousands of people, just as Sohaku planned, before his friends can stop him. The closest Sohaku gets to redemption is realizing that he has no chance of succeeding and quietly admitting defeat.
Ensemble Darkhorse: Bunshichi Tawara is this amongst most the fandom. Though beliefs that he was the strongest fighter in the school turned out to be false, his devil-may-care attitude and fighting skill has made him particularly memorable.
Masataka Takayanagi is well liked among the fandom, despite being Demoted to Extra amongst the main cast for some time. He returns to prominence near the manga's final arcs, defeating Mitsuomi in a brutal fight and culminating in a battle against Souichiro that buys enough time for Maya to remove Souichiro's Red Feather abilities for good.
You can find plenty of fan art of Emi Isuzu on deviantART. Not surprising, since a surprisingly high number of people on the site are fat admirers and view her as a Big Beautiful Woman, whether the author intended it or not.
Fashion-Victim Villain: Mitsuomi. He without a doubt has the worst sense of style in the series. He thinks his outfits look awesome when everybody else insults them. It's lampshaded by Masataka when Mitsuomi wants him to wear battle-clothes passed down through the Takayanagi family. These clothes are little better than the clothes Mitsuomi wears, and Masataka wonders if a bad sense of style is hereditary.
Relationship Writing Fumble: It's almost sad, really, how Aya's Yuri scene with Chiaki went way further than she ever did with Souichiro. That scene was, of course, meant to appease certain viewers but to be fair even Chiaki lampshaded how even she is more aware of what to do with Aya than Souichiro ever was.
They Wasted a Perfectly Good Plot: As the buildup to the last battle came along, one of the Takayanagi brothers, likely Masataka, was hinted to be the Tsukuyomi to match Souichiro, the Susano'o, meaning that there may have been some sort of power-up for Masataka waiting in the wings, but in the end, Masataka just fought Souichiro all out, losing a hand in the process, and it was left up to Maya to free Souichiro from the power. However, as there wasn't anything explicitly stating that the entire thing was more than symbolism, this may just be an example of reading too much into the situation.
Unpopular Popular Character: As the story progresses the less seriously it seems to take Masataka, which is odd as he is shown to be one of the best fighters in the series, second only to Maya Natsume, the top ranking Enforcers and his brother Mitsuomi. His prowess is such that he can take on 80 men in one fight and his fight against Souichiro early on in the anime is one of the most brutal depicted. As explained in Ensemble Darkhorse above, this is eventually averted.
The Woobie: Shin, just Shin. Poor guy is completely under surveillance by the Takayanagis to oversee his power development, and they even recruit Mana Kuzunoha as his fake girlfriend to help them do it. Maya's relationship with another guy ends up sending him over the edge from jealousy, and when he tells Dogen that he is happy with the way he and the school are currently, finally trying to make a fresh start after his brutal fight with Bunshichi Tawara, he is manipulated into activating his Dragon's Eye and going berserk again. It is no wonder he eventually decides to commit suicide with Mana's help.
Jushi Mataza's story is rather heartbreaking as well, if only because his brother was a massively abusive and hateful prick.