I was wondering if anyone knew the name of this BL manga I read a few years ago, it was ab...

I was wondering if anyone knew the name of this BL manga I read a few years ago, it was about these two guys who were dating and one of them died(I think it was a train accident? I don’t remember) and the other one commited suicide shortly after(i don’t remember if it was because of grief or smth else) but centuries later, the one that committed suicide woke up because apparently his parents had spent money to preserve his body until a time he could be resurrected. When he wakes up he meets an Android that was designed to be a replacement for his old lover, but because he is a machine and the first model he’s not an exact copy but none the less the two bond. Eventually the MC wakes up one day to see the Android had been taken and replaced with another one that was a better representation of the real guy who died, be he wanted to old android back instead so he went on a journey looking for him? That’s as much as I remember and it was really sad and it would be amazing if someone could tell me the name so I could find it again!