
Could someone please explain the second story to me? Im so lost.

High school kid Kaji is in love with a sensei at his high school. In order to move on from this unattainable unrequited love he decided to hit up a version of grindr to fall in love with someone else.
They both used fake names. Tama and Yuuki.
Kaji as Yuuki pretends to be 20 and a college student.
They meet up. Probably both recognize each other. But Kaji definitely does and it turns out to be his unrequited love. Kaji jumps Tama in the park.
For a year they meet up on the weekends and have sex. At first Kaji was the top but it slowly got switched. Now I think Kaji bottoms most of the time and Tama is in control of the relationship.
Kaji can't handle holding back the truth and confesses part of the truth. About how he's a teenager in high school. Their relationship freezes out a bit?
But it seems they are getting back together since Kaji is graduating. And Tama aka Yoh mask-sensei is fully in control of this relationship as an S with Kaji as an M.

I think they are more reversible. Hiroki wants to make a mess of Tama and be made a mess of. I'm at least going to believe they are.

Oh I'm not denying the sex positions of them being a seke couple (reversible). But that's different to someone being an S or M or being in control of the relationship.
Kaji started out as the seme and seemed to be driving the relationship. But Tama took control of the relationship. Even when Kaji was topping Tama was in control of how it went down (except for the first times when Kaji lost it).
We could see this develop over time as Tama took more of a lead in things. He was teasing Kaji. The games they play, etc.
However at the end, we have Tama in full control (confession broke the illusion) most likely due to the risk to him and Kaji's guilt. Tama has also realized he's a Sadist who enjoys bullying/teasing/punishing Kaji who seems to enjoy it and probably because he feels he deserves it due to the LIE.
However, the sex positions definitely switch up.

there's no excuse to what sunbae did to poor sunhwa, but i just wonder if he did what he did because he knew about the rumours going around about him. he was ostracized maybe bullied in some ways and here he saw sunhwa, cute and naive kid who was so gentle it irritated him so he just wanted to crush it all at once. i hope sunbae looked at sunhwa that way because he finally saw his chance to apologize for all the fucking horrible shit he did to poor honeyball of joy. if not and he is still an asshole i hope his wife just poisons him or he dies a horrible slow death...

I LOVE the perfect way you put this! :D
MAN THAT SOUNDED SO DAMN SCARY!!! because he is like the "after care" team for an assassin, cleaning the floor from dead corpses. idk that's the feel i got
SAME! And that also makes him seem fucking awesome