Two years into their relationship, Takahiro is in an accident and loses all but the earliest memories of the man he's built his life with. Everyone agrees not to tell Takahiro about what their relationship truly was, and so he struggles to build a friendship with someone he barely knows, frustrated by his missing two years but refusing to be given spoilers.
SPOILERS: I appreciate that he never gets his memories back but comes to love his partner a second time.
Mou Ichido, Nando Demo