Hikaru's reveal makes sense, and I prefer it to the speculation. 

Another thing of note - those interested in 'BL horror with some gore' may not find this as interesting as MadK. The Summer Hikaru Died's lgbtq connection revolves around teenage Yoshiki's attraction to his friend Hikaru, and the thing within Hikaru's processing of those feelings - so yeah, it's not BL in the sense that western audiences are trained to see that genre and its stories. Still a great series, through.