A reclusive young man named Junkichi finds himself living out his dream life with an AI-equipped robot girlfriend, Lin. He raises her into his ideal partner while learning about love and intimacy through their interactions. Unbeknownst to him, however, Lin bears a striking resemblance to the woman he has secretly admired. As they grow closer, Junkichi finally confesses his feelings and wins over his crush - but just when things seem perfect, Lin mysteriously disappears without a trace... leaving behind only the echoes of her newly awakened emotions: "Aishitemasu, Sayounara."

引きこもりだった純吉は、AI（人工知能）搭載のロボットリンと夢の同棲生活を送る。自分好みの女に育成して理想の恋人へ仕上げていくのだが、実はこのリンは純吉が片思いしている女性に酷似したAI。童貞だった純吉はリンのおかげで女性との接し方を学び、そして遂に片思いの彼女を手に入れることができるのだが、AIリンの居場所はどこにもなくなってしまった… いつしか感情が芽生えるリン「アイシテマス、サヨウナラ」。