Lighting Serenade /Monoshinkami/

In a universe where soulmates can hear their other half singing in their minds, Kaminari Denki gets excited when he hears TWO voices singing in his head one day, only to have his world crash around him when he is told that they must be hallucinations brought on by the stress of his powerful quirk.

He is promptly sent to a mental hospital to gain control of his new reality where he meets two boys who are soulmates with each other: Neito and Hitoshi. They become fast friends, but Denki horrifyingly sometimes finds himself wishing that he was their soulmate, too.

Join Denki on his way to self-discovery, self-acceptance, and self-love as he bonds with a blonde agent of chaos and a purple-haired insomniac as they explore their own soulmate connection as Denki wishes he had what they had, and they wonder at times why they were stuck with each other instead of someone as positive and easy to get along with as Denki.