the ultimative mother-con manga:
Young man meets his reborn, non-blood related mother who turns his life around.
But, since she is now a different person(she only inherited her memories, she's not really reincarnated or reborn),
it would be ok if they marry so his previous mother will now become his wife!!!
Maybe there will be even a plot twist and she's just possessed or did attain the memories of his deceased mother since she was is a similar situation, maybe even at the exact same spot where his mother died and the author is just playing on the incest theme here (like he teased in the KissxSis manga)?