Omoide Emanon has a lot of poetry and a pure atmosphere. I felt very calm (but quite bored) when i read it. There is only love and beauty, with good art. The characters are well introduced and have depth.

However, the plot is a bit dull, there is a lot of nonsense like :

[spoiler]
mother loosing part of their dna memory when they get a child (???)
[/spoiler]

Nothing will really happen in the manga, and the plot twists are spoiled in the beginning. the characters pretty much spend the manga talking.

It was boring to read but the overall atmosphere and the immortality depiction is pretty well managed by the author, so i would still recommend you reading at least the beginning. If you don t really enjoy it, consider dropping it since there will be nothing much more happening.