Chuugoku Yome Nikki 1-6
This one is a bit odd to comment on seeing as it's a manga written by a Mangaka about his own marriage.
Essentially it tells of a 40 year old "otaku" mangaka and his 26 year old chinese wife, focusing on the odd moments of cultural difference that the wife has with Japanese culture.
The stories themselves can be cute and amusing.
However there's some underlying unintended themes that make me quite uncomfortable reading it.
Firstly there's the Mangaka himself, reading the Manga got me the sense that he's, in general, a very unhappy person and that he sees his wife as the only positive thing in his life, which I find to be incredibly depressing.
The other is the marriage itself, there's this undertone to the story which implies that older Japanese man that can't find a girl to marry in Japan are marrying young Chinese women, which in turn are marrying these older Japanese man because they want to get a better life outside of China. This is of course never explicitly stated, and I'm sure the author himself isn't even self-aware of it, but the amount of Japanese male/Chinese female marriages referenced in the story and even the description of his meeting with his wife give a pretty strong impression of this.
If you can read it and without getting the same interpretation as I did, it's a pretty pleasant manga, the cultural differences between the Wife and Japanese cultural make for some entertaining situations, and there's some heartwarming feeling to the story as the author seems to think highly of his wife and his wife is usually depicted as being very enthusiastic and happy with her everyday life.