HAL

Kurumi's heart was broken by the sudden death of her boyfriend in a tragic airplane accident.​ Forced to carry on without her beloved Hal,​ she fell into a reclusive and joyless existence.​ Kurumi had given up on the world,​ but a brilliant scientist devised a plan to win her back.​ By melding futuristic technology with the binary equivalent of human emotion,​ they created an ultra-lifelike robotic surrogate to take Hal's place – and lure Kurumi from her shroud of solitude.​ Resistant at first,​ this shattered beauty slowly yielded to her feelings of longing – and took comfort in the company of a robot.​ Though their unique bond grew stronger with each passing day,​ Kurumi and Hal would soon discover that nothing about their artificial love story was quite as it seemed.​ (Source: Funimation) — Description from AniList community (anilist.co).