I Woke Up Married with Children

[Both are each other's first and only + sweet romance + married first, fall in love later (in a way)]

Song Wensi and Chen Lingnian wake up one morning having both forgotten their relationship history and the fact that they are married with children.

Song Wensi can't understand how she ended up with someone like him, let alone having two kids with him without a care in the world. Chen Lingnian is just as baffled. He clearly remembers having a crush on someone at university, and even swore he would never marry anyone else. Those words are still fresh in his mind, so when did he fall for someone else?

Song Wensi: When did I go blind?

Chen Lingnian: When did I fall for her?

They can't stand the sight of each other and wish the other would disappear as soon as possible.

But as their dislike goes on, they somehow end up getting all lovey-dovey again.

[At first, as they lose their memories, their past feelings disappear too. The leads are really awful to each other at the beginning!]