Hikaru ga Shinda Natsu is an ongoing manga written and illustrated by Ren Mokumoku. First released in 2021, it has been serialized by Young Ace UP.
"So, Hikaru is no more... If that's true then..."
Yoshiki and Hikaru are two boys who live in a certain village. They're the same age and have always been together growing up. But one day, Yoshiki noticed that "something else" has taken Hikaru's place. Even after learning of this, Yoshiki still wants them to be together. And so, his life with the "something" that looks like his friend begins.
At the same time, strange incidents keep occurring in the village...
When running laps is described as torture, Yoshiki remarks that Hikaru's intonation of the word "torture" was a bit off. Feeling Hikaru has got to remember something when he was lost, Yoshiki also comments on him not having a word to explain himself, and does he know how much he worried everyone. Questioning if he can ask Hikaru something a little strange, it has been on his mind for some time now, namely how Hikaru with him really is different to the Hikaru he knew. Seeing it, and registering the dark flesh like mass coming from Hikaru, he gasps at being held. Under the circumstances, Yoshiki thinks either way, Hikaru is already gone so even if it is fake he still wants to be with him.
Using Kansai dialect, Hikaru says his pronunciation never crossed his mind. Unable to remember what happened when he went missing for a week on a mountain, Hikaru says for Yoshiki to give it a break already, and when is he going to quit asking that. Querying whether Yoshiki was lonely because he was not around, betting he cried, Hikaru jokes how Yoshiki did not want him to be left here alone. Wondering if Yoshiki's question involves him professing his undying love, Hikaru's carefree and joking attitude is gone at hearing what it is. Shocked, as worms fall out his left eye, Hikaru feels his imitation was supposed to be perfect. With the substance growing from his head, Hikaru embraces Yoshiki and he begs him to not tell a soul. Hugging him, the being occupying Hikaru's deceased body says for the first time he was living as a human, where he got to enjoy school, friends, and even ice cream. Explaining that who he is as a person and his body are both borrowed, Hikaru adds that he loves Yoshiki. Tearful, Hikaru says he does not want to kill Yoshiki.
A teacher mentioned by Yoshiki as one who would make Hikaru run laps in this blistering heat. With home-room in session, Hara details how a body was discovered over by Kubitachi this morning. Stating that they are saying it is not foul play but still kicking up a huge fuss, Hara says for students to not be surprised even if they see police cars around.
Approaching Yoshiki and Hikaru, she questions why hasn't the lord brain snatcher descended yet. Crying out, Matsuura warns them to not come closer and leave. Appearing as a deceased appearing elderly lady, she pants for breath. In her abode, Matsuura decides she is not opening the door, then wonders who would come in the dead of night.
In class, Maki approaches Yoshiki to say he is on his hands and knees here. Shut down, Maki pleads with Yoshiki to just come with him for a sec, then asks why the heck not. Speaking to Yuki to say he always takes the East gate mountain road when he is walking home, with construction going on he finds the other trail scary as hell.
Cleaning with other students, she asks what Maki is yammering on about now. Heading to the trail, Yuuki answers she is not really scared, while appearing to be. Having seen a woman collapsing into tears, Yuuki is sympathetic to her plight.
Called Asa, with Maki sharing his scary story, she finds it super creepy but he has her full attention. Confirming she dumped the trash, Asa speaks to Yuuki on how it is something so scary they cannot see it. With there having been an awful lot of dark whispers around the village, Asako finds it is getting suffocating.
Messaging Yoshiki concerning super spicy wasabi flakes, Kaoru says to buy some since they are out. She is in her first year of middle school.
Introducing herself as a housewife to Yoshiki, she is aware of a malevolent presence from the mountain. Finding it is now beside Yoshiki, she warns him that too much prolonged contact will result in him changing as well. Providing her number, Kurebayashi responds to Yoshiki's message asking if he would like to talk.
He passed away when Hikaru and Yoshiki were in the fifth grade. While it was said it was a workplace accident, it is noted how he went to the mountain.
Heading into a store for ice cream, there is only a papico left. Outside, Yoshiki and Hikaru discuss the teacher, Hara. Out of curiosity, Yoshiki asks whether Hikaru remembers anything from when he went missing for a week on the mountain in the distance half a year ago. Wanting to ask him something, Yoshiki says he is different from Hikaru. Stunned at the words, Hikaru has worms coming out his eye while thinking his imitation was supposed to be perfect. With monstrous details, Hikaru hugs Yoshiki and begs him to not tell anyone that appearing like a human, he has got to enjoy living like one. Reasoning that Hikaru is already gone, Yoshiki feels even if it is fake he wants him here.
The being inside Hikaru begs Yoshiki to not tell anyone