It absolutely can. I think "kinks" can be done in a vanilla way. To me, "vanilla" comes from the overall tone of the work. I think this also counts in real life; engaging in pegging, bondage, et cetera, can be done in a sweet, loving way, but also in a role-playing, "kinky" kind of way. It's all about context.
Also, I think it's worth exploring our collective latent insecurity in masculinity that male anal play is considered a "kink" to most. Food for thought...
I see where you are coming from, but I feel that is a re-definition of the word "vanilla". Going by the Savage Love usage, vanilla is the opposite of kink. No moral judgement, just basically saying missionary is one end of a spectrum.
However, that said, you have an excellent point about how "vanilla" is used on Fakku. Given that we don't have any definitions of the tags, from what I have seen, "vanilla" on Fakku is if something is loving and sweet. There was a "vanilla" incest story a while back.
 I can't speak for others, but I think any anal play is a kink, regardless of gender, but I feel out in the wider world, there is homosexual subtext with with male anal play (i.e. a fear of gayness).
Well, Vanilla doesn't infer if the content is sweet or loving at all. It just means it isn't on the extreme end of expectations for sex. I'd say expecting your partner to take a dildo (or even a penis) in the ass is pretty far on the extreme end and far enough away from "vanilla" to exclude the tag. I'd say the same if it were a female getting anal as well, though pegging does tend to get put into a bit more extreme a case since it is the penetrative partner being penetrated which is a pretty big reversal of sexual expectations.
I don't know about "fear of gay" but I in general fear things going into my backside. I had a probe up my rear for a medical exam and that shit was uncomfortable and at times painful. Not a sensation you forget. Guh... *Shudder*
Ya, I hear you. Maybe they are just basing it off of the relationship, rather than the acts? But pegging is a kink, so I think most people don't consider it vanilla.
Hmm... this is a good example of how a Master can be dominating but also very caring to their S. Although she wants to play with and tease him a lot, there's a lot of affection going into it.
Ah yes...Girls forM.
Well, at least he seems happy? If they're both content with this relationship then that's great, you know.
And at least it had a nice ending. I mean, she said she loves him and is even willing to have sex with him (that's more than many girls from this magazine would allow)...So at least she does these things to him out of love...?
Hentai related to Anal Research Study Record ~Sensei is My Test Subject~