Ikuru is going to die soon. He lives today, because of another girl's body parts that were grafted to him long ago. The parts that had once saved his life now threatens to take it away. Weighed by the pain and loneliness of his condition and his dilemma, he decides to request the companionship of an AGH-RMS, an "Ai-Ren." These artificially generated humans have their personality and disposition artificially engineered to specification. Their origins are a mystery, but they currently serve to comfort terminally ill patients. When Ikuru's AGH-RMS first arrives, he is surprised by her decisively childish naivite. He names her "Ai" and rediscovers life, love, and how moments he once took for granted can take new meaning when shared with someone else.
However, the futuristic human society seems to be on the edge of an unavoidable apocalypse while Ikuru and Ai live in their own sweet little bit of paradise. Ikuru finds solace in Ai's love, but AGH-RMS can only maintain their engineered persona and memories for a short time. Ai faces death as well.
I recently re-played Kana, Planetarian and a few other baww-ish games/mango. I dont want to feel depressed again ;_;