If you want to specifically identify characters based on what medium they come from, the character's enjoyment of that medium should be expressed in the sheet. If Symbiotes were Kamen Rider characters or someone made an ELS character, then I wouldn't be surprised for Satoshi to recognize them because his "likes" specifically list Kamen Rider and Gundam. However, there's no mention of comic books, more specifically Marvel or Spider-Man, and by that, it's metagaming.
Nope, because it is entirely possible to identify a character without liking the story they are from. I could identify characters from stories I don't like or, in some cases, have barely ever
seen.
You are taking an extremely limited idea of what knowledge characters are allowed, which, if it was held to, would seriously impair people's ability to RP. This is
not meant to be an adversarial RP, we are not here to fight each other, and character sheets are only an overview of a character (in particular their abilities), not determinants of their entire personality. Lantz made it clear in-character that he knew of comics well before this event happened, and no-one (in particular Elf) complained about it then, so there is absolutely no justification for complaining
now.
The point of this RP is to role play as realistic people. Realistic people don't have knowledge, personalities and abilities that can be perfectly represented by a page-long character sheet. So, no, Lantz absolutely does
not have to include everything Toshi knows on the sheet, and if you think he is meta-gaming because of this then I am absolutely
certain you will see me and just about everyone who is playing this RP
properly as meta-gaming as well at some point. What you are arguing would absolutely wreck the RP if it was held to, so I make no apologies for saying that I
absolutely will not hold to it if such a situation ever comes up for me.
If my characters should reasonably know of the existence of an enemy on the basis of how I see them in my mind, then I will say that they know of them, regardless of what my sheet says and, even, whether or not I have mentioned it in-game before. If you don't like that, then tough shit, because this RP is not meant to be about who can make the most powerful character and win every fight.