In volume 19 of the manga, some of the author’s notes and sketches of this antagonist’s early concept and design were included as a bonus page, and in it, it states that she is bisexual or.
Officially, Eijiro Kirishima’s sexuality has not been confirmed, so there is no precise answer to this question. Usually, this means that a character is heterosexual, but that doesn’t necessarily have to be true; the fact is that the canon did not address this issue.
There is no confirmation on his sexual preferences but I do have a gay brother and I myself am bi so from experience I can tell you he doesn't show anything that would indicate that he is definitely gay if anything I'd actually say he's bi but not gay.
On twitter and tiktok, there is a lot of discussion of Kirishima being gay or queer coded and discussing if its intentional or not? So I was wondering, how valid is this interpretation or something or is it fans reading too deep into it? The important thing to recognize is that MHA is Japanese.