The idea of heiji being mixed is in my opinion not impossible tbh
Ive made my points in the comments already but I so wanna do a reblog version so I can add pics to better explain my point + maybe for it to reach more ppl bc I do think it's an interesting thing to discuss.
Now first and foremost heiji specifically states he got his dark skin from his grandpa
Which is pretty important information since this means that the brown skin is likely genetic/something he was born with.
Intact heijis child self is in fact brown, just as brown as he is currently
Hes not any lighter than how he's usually portrayed. So I think its unlikely he just got darker over time through sun light/ UV light.
He also has no tan lines from as far as we can see
And I've never seen anyone portray him with tan lines.
Overall we don't know where heijis grandpa is from or what he looks like so we can't be sure but this leaves up for open discussion so a harmless headcanon like yours isn't bad do not worry about that it's not like ur going around and claiming it's canon lmao. So a Blasian heiji headcanon is not that bad tbh (since that's my personal headcanon too) but overall I do think South Asian influence is possible too since lots of South Asians also how brown skin. (Or any other ethnicity/race where brown skin is common)
Since heiji is from osaka Japan and we mostly see him around Japanese culture his entire life. It's hard to find influence from other culture that could help determine what he could be mixed with (if were going by the idea that he is)
Overall it's up for interpretation shrug ¯\_(ツ)_/¯ but I do think the brown skin is definitely natural/genetic
Ill gladly hear out on yalls opinions on this as long as you are chill abt it
