I think my comment is either glitched out on my side or everyone but following the ambiguous part I said that The Night Beyond The Tricornered Window is similar in that aspect but labelled BL because it was published in a BL mag so it basically depends…people think Killing Stalking isn’t a BL(hilariously) just off their presumption of BL needing romance when it’s broad and not that confined. Also go read Requiem of the rose king

It’s been 30 years…jk came back and saw that some probably new readers are confused about whether this is BL or not well copying my past answers I’ll answer that:
1. “Sensei said on twitter that it isn't a BL but you're free to see it as one. Some sites put it under BL which Sensei says is not but doesn't mean that you can't ship. As for their blood drinking scenes that are super sensual they say it just happened LMAO hope they continue feeding us such scenes”
2. “I was in fact the commenter but they don't mind that perception and the English license is by a BL publisher which obviously has to go through the author so labelling it BL would be okay too!”
3. “Also the new volume is coming Japan the author joked about how the cover is a bit more BLesque. For those who are confused this isn't a BL cause it's not published in the mags for it "it's aimed to the general youth demo but depicts relationships between male characters" these are the author's words in a reply to someone on twt”
Now for some words of wisdom from an old fujoshi. BL is huge I mean massive and diverse basically that it is a genre with sub-genres most see it as romance but BL isn’t solely romance. Not every BL will come from a BL mag in fact our roots are actually in shoujo BL is technically at its heart shoujo that’s our mother we have shounen BL i.e. Blue Flag and Seraph of the End. This manga in particular is seinen and we do have Double as an example. What you need to understand that if the central romantic or sexual relationship is homosexual by all technicalities it falls under BL but if the author rejects then by respect we’ll just say queer for example TSHD is a BL but we’ll call it queer since the author doesn’t see it that way. “But the relationship here is pretty ambiguous