[Arturro]

Originally Posted by _kurusu_

Arturro, Zen is the hero and he still is, but don't forget there's the heroine too Besides, he will never be a secondary because he just can't be. Once you're the main you keep that role no matter if there're some chapters with less spotlight than in others.

The difference between protagonists, secondary and tertiary characters is their importance for the story, and if they can be replaced by other characters. Protagonist is someone who is irreplaceable for a story. In "The Disappearance of Suzumiya Haruhi" Haruhi is absent for most of the story. But without her existence that story wouldn't make any sense. If character could be replaced, but not by anyone, then he/she is a secondary character. In Zero In manga Kina Monjou was replaced by Shikie Misono. Both are secondary characters. And both have more importance for Zero In story that Zenkichi has for Medaka Box.

Since chapter 8 Zenkichi could be replaced by any other character, in most cases even a random schoolmate. Try to read again those chapters imagining that in place of Zenkichi someone other is talking - Akune, Nabeshima, Shiranui, random classmate. Such exchange won't influence the plot even a little. In last two chapters he has a role of sidekick, so he couldn't be replaced by anyone, but both Akune and Nabeshima would work in his place as good.

Arturro is gonna kill you

It's true that I'm a little bit antisocial but not enough to persecute people because of their opinions or hopes

It's true that Zenkichi development is going in direction I dislike, but at least it was hinted, that he will have to power up by lots of efforts, not by magic tricks. I could stomach it (heh, I even like HSDK).

Originally Posted by TheAlucid

Didn't they already reveal what the flask plan was about? I thought the headmaster fellow said that the point of the plan was to turn normal people into abnormals several chapters ago.

You're right, there wasn't any real explanation, just some informations were confirmed and a few new informations were revealed. Still it's an improvement.
As an explanation I want to read: what are abnormals (what is source oftheir supernatural powers), who is behind flask plan (if it's just principal, how he is so powerful), some real flashback about Medaka family and Zenkichi and Medaka connection. And why is anyone, except those class 13 willingly working as guinea pigs, learning in a school full of freaks, and where anyone could be injured, disgraced of even killed by one of those freaks.