"Hikaru" is an AroAce character! He is confirmed as an AroAce character by Mokumokuren themselves and has even asked the fandom to stop denying how important "Hikaru" being AroAce is to his character! "Hikaru" does love Yoshiki in his AroAce way! Their relationship is very Queer!
ALT The Summer Hikaru Died manga panel shows Yoshiki putting his right marked hand to put over his mouth as he says, "..." "Hikaru" is talking with a smile as he says, "I mean, I do understand some of it, y'know? Like, I know when somethin's supposed to be sexy......An' I like food 'cos it tastes good, but the feelin' of hunger itself ain't a big deal for me." The two little images next to him show "Hikaru" and Yoshiki in an older panel in the gym with the caption saying, "Two people alone in the gym->Feels kinda scandalous." The next picture shows a minded meat outlet that points to, "tasty, so I'll eat it. Rie says with a slight smile, "Well ain't that somethin'...So takin' in impurities an' souls is like eatin' to ya..." "Hikaru" looks at Rie as he moves his hands in a circular motion with Yoshiki looking at him as he says, "Hmm, not exactly...Souls are just so pure an' amazin.' I can't help but go like 'wow!' around 'em." Yoshiki says, "Then......What do souls feel like to you?"
ALT The Summer Hikaru Died manga panel shows Yoshiki grabbing his hat off his head with his right marked hand in distress as he looks down with the ocean behind them as he says, "Stop it! Stop..." The next panel shows "Hikaru" looking to his right side as his eyes are obscured with his left hand on the top of his head as he says, " I...Well.......It was real fun bein' with ya, Yoshiki...Maybe I was just a replacement for the real Hikaru to ya......But ya gave me a lot to someone like me. And I love ya." The next panel shows "Hikaru's" feet in in the surf as he says, "This feelin' probably ain't nothin' like romantic love or friendship. But it's truly how I feel. Not as Hikaru, but as the monster I am."
ALT The picture shows Mokumokuren's bluesky post that says, "Anyway, what I want to say is please stop denying the aroace element in order to protect the homosexual element. Both elements are equally important. π’."
ALT The picture shows Mokumokuren's bluesky post that says, "I'm not angry about anything! Manga is fun because many people can interpret it in their own way. However, I want to say that the elements of AROACE are not queer baiting, and that a romantic interpretation is not the only correct interpretation."
Hikaru isn't asexual, he loves Yoshiki romantically.