A Tunnel of Spring Rain

Every morning like clockwork, Asahi comes over to wake Eiji up. Eiji is Asahi's big sister's fiancé - but ever since she passed away three springs ago, Asahi takes it upon himself to be there for him. Is this really out of the kindness of his heart, or is there another reason why Asahi always wants to be by Eiji’s side? (Source: Futekiya) *Note: Includes the one-shot VOICE*