Looking for a yaoi manga where the MCs are in a long-term relationship (till one of them become a senior)

So I'm looking for this particular yaoi manga where the MCs are lovers, but unfortunately their fams are against their relationship. They decided to get married (I'm not sure about this one, i forgot) and they live in Germany. In the latter volume, the uke has died due to old age (or illness?) and the seme has become a senior citizen. He has a neighbor, a little bit, to which he told the story of their life.

I'll be happy if you could help me find the manga! :D