The Summer Hikaru Died, Vol. 1 by Mokumokuren, Ajani Oloye (translator)
artwork is awesome too! Yoshiki's best friend disappeared into the mountains six months ago. Someone (or something) that looked like him, behaved like him and had the same memories come back. But it isn't the same Hikaru.
That doesn't stop Yoshiki from being pulled towards him.
It took a bit of time for me to get oriented to what was happening. The start is all over the place and I couldn't figure out who was who and what was going on. But once I got sucked in, I couldn't stop reading. And those last few chapters were so intense, I can't wait to read what happens next. :)