Okay, so...has anybody ever bothered to query where the majority of the parents for some of these kids who are involved in Ragnarok, YOMI, and other minor gangs are? Aside from those who we know the parents are around but are mostly background characters (Kenichi), or they've been orphaned or abandoned (Miu, Tanimoto), or their relatives may in fact be subverting Adults Are Useless when it comes to fighting Yami (Freya's grandfather), but for the rest, WHERE ARE THE PARENTS OR RELATIVES IN ALL OF THIS? Do they even know their kids are being made into delinquents or are being molded into martial artists who use the killing-fist philosophy? If they know, do they even care?
Well...,for most of the YOMI guys, the Japanese ones most certainly come from the Kuremisago, the american ones, apparently were put into training by their family, we know Tanimoto´s way, apparently Jihan is an orphan, Boris is an especial commando thing at the care of Alexander, as far as i know little thai boys practice martial arts since early childhood, so Tirawit could have seen being taken by Agard as something really good, and well... about Ryuto I have no freaking idea.
Several times during the Ragnarok arc, Nijima sabotages Kenichi's attempts at avoiding further fights, deliberately ensuring that new fighters rise to the challenge and defy him. In retrospect, Nijima isn't doing it For the Evulz - he's running an experiment, testing if it's possible for someone to rise above their station. Why? Because if Kenichi can do it...then so can Nijima. Cue the latter reinventing himself as the charismatic leader of the Shinpaku Alliance.
Overall, it seems like those who practice Katsujinken are stronger and more skilled than the masters and fighters who practice Satsujinken. Thinking it over, it is pretty obvious that in a martial arts match, especially of the kind seen in Kenichi: The Mightiest Disciple, it is actually HARDER TO NOT KILL than it is TO KILL. In other words, the Ryozanpaku are as skilled as they are precisely because that despite the fact they train everyday, they also train to hold back in a fight, so they do not kill their opponents. This leads to them having far more control over their techniques and skills in comparison to Satsujinken, whose main goal is to kill, so they don't hold back, meaning they can't refine their skills.
Furthermore, since the Katsujinken don't kill their opponents, their enemies can keep coming back for more. To put it another way, the Katsujinken probably get a lot more practice.
Related to the above - why is so much made about Apachai reaching his full combat prowess after finally learning to hold back? As a Dou-type fighter, he gets more powerful the more emotional he is, and the Elder notes that Apachai's brute striking power has reached reflexively murderous levels. He only successfully manages to "hold back" after learning how to train Kenichi without accidentally killing him. For a Dou-type fighter like Apachai, who has always been afraid of actually killing someone when he didn't want to, this means that for a large part of his life, he had NEVER trusted in his abilities and so could never strike with full efficiency and intent (unlike Agaard, who always intends to kill with each strike). It is only after Apachai learns how to train with Kenichi that he can trust that he has the control to not kill unless he actually means to, and so is free to raise the strength of his attacks, able to successfully use and counter Muay Boran techniques on Agaard with the same level of power.
Remember when Odin was first introduced? He had a yin-yang button on his collar similar to the one Kenichi wore on his jacket, establishing him as Kenichi's Evil Counterpart. In the same way, Saiga Furinji may well be set up to be an Evil Counterpart to Kenichi as well because they're both wearing gauntlets (in Kenichi's case, his gauntlets used to belong to Saiga, who points out as much), they both have close ties to Ryozanpakou as disciples of Hayato Furinji (former in Saiga's case, plus Hayato is his father), and has been noted on the Character page, Saiga looks like a blond version of Kenichi.
The Reveal that Saiga Furinji was Good All Along and framed by an impostor handily explains the incronguity between his heroic present day deeds such as rescuing Miu and Kenichi as "John" and "his" past atrocities and him being the leader of YAMI.
Still doesn't explain where he's been all this years and why he hasn't shown up in Ryozanpaku, though.
Flashbacks show him, along with Senzui training Kajima, so Saiga likely has been splitting time between being the One Shadow, and secretly opposing Yami.
It's interesting that it's some bug in the plot that prevents Siegfried from either winning or severely damaging the main foes. Against Berserker, he fought on top of a fence where his style could not be applied fully. Plus, he could've Requiem Bombed him into the ditch Nijima dug up instead of the sewage water. His battle with Spark of Yomi was in defeat because the Shinpaku alliance interfered with their bout. Even with the Dof D Tournament, the only thing preventing him from curb stomping the Capoeira team was awaited orders to do so and ultimately fatigue from arriving from Training from Hell.
Not sure if this actually counts as Fridge Horror, given what we've had revealed to us up to now, but...remember back in Chapter 455, when the mercenary John told Kenichi that he's frequented Nijima's Shinpaku Alliance website? Well, John's been revealed to be Saiga Furinji, the One Shadow, in afat suit all along...so does that mean he's got all the info on the Shinpaku Alliance and could use it against them any time? Fortunately, the One Shadow was actually Saiga's imposter. The real Saiga is one of the good guys.
The "horror" part may be subverted thanks to Castor. Remember that the headquarters was attacked very early in the YOMI saga. They know where it is, they just don't care.
When Miu Almost Kiss Kenichi at chapter 423, the Elder was full of Killer Intent against Kenichi. Itís funny, until you realize that the story seems to imply that Miuís mother was killed by her own husband giving the Elder a very good reason to act like that.
Especially when a lot of connections between Kenichi and Saiga are referenced.
Silkwat said that eating fruit drenched your blood thirst, and we see that he eat fruits ALL of the time and still is very brutal. The horror part is how bad would he be if he didn't ate all that fruits.
Tsutomu Tanaka is a salary-man who happens to be an exceptional martial artist and who has a habit of always speaking to his wife on the phone. In the most recent chapter (521), after having pulled a Big Damn Heroes moment by intervening in Isshinsai's (Kensei) fight with Kenichi and Ryuuto while talking to his wife on the phone, at one point he stops to make yet another call, and Kensei kicks the phone out of his hand, around the same time that the Ryozanpaku masters are discussing his past, where in flashback we see his former father-in-law and his then-fiancee. Then Kenichi gets hold of the phone, quickly talks into it to urge the wife not to go near the amusement park because it's dangerous...only to realize that on the other end is a generic telephone automated voice recording. Which means very likely that it wasn't only Tanaka's father-in-law that Kensei killed in the past...he also killed Tanaka's wife and unborn child. Which means Tanaka hasn't been right in the head at all since then, and he's been having imaginary conversations with a wife who's been Dead All Along.