Though none of us, to my knowledge, has the Highlander gift of immortality, the Japanese aim seems to be to take us as close as possible to acquiring it. Albeit in a creepy cybernetic way, 'Oboe' is designed to accompany the elderly; its purpose is to attain the knowledge, experiences and, more or less, everything that reminds you of your loved ones before they pass. This way much of their essence will live on to the future and the coming generations.
Immortality on its own would probably make little sense after all. We can hardly make do with one lifetime, who wants to actually live forever? It is such an awful lot of effort and time, so let the robots do the heavy work.