Hi! I remember watching this anime, not sure if it's a full length film or an OVA where there's this robot girl who was implanted with a dead girl's memories then a human boy finds her in a garden and they both fall in love with each other. My memory of the ending is a bit hazy but I think it was something like, the robot girl's body was weakening so the boy asked the scientist/doctor to implant the girl's memories in him. Thanks!

The english translation of the title was I Only Want Happiness or something along those lines. Sadly I can't find it, been looking for the movie for ages...

Hotori - Tada Saiwai o Koinegau