No time traveling involved but a divorced couple cross paths and the ex-wife sets out to change her fate and get a bit of revenge on her ex but feelings happen and previously unknown information surfaces that change everything for all involved.

Married couple who have fallen out of love with each other over the years and gradually began to resent one another and want to divorce, wake up as college students (pre-relationship) and have the chance to change their fate.

Same basic plot, popular, smart, handsome guy ends up living with relatively normal girl after accident.

The premise is the same. A couple for some reason or another breaks up and then the man starts a business and becomes successful. The woman then begins working at the company and the exes have to interact and come to terms with things from their past. The main difference is that Cunning has a way more light hearted feel and there are more funny moments.

Has a similar feeling. It's kind of like if you combine the emotions and relationships for Pete/Ae and Tin/Can into one couple you'd get Ai No Kotodama

Female leads are similar in personality and their lives are improved from their friendship with the male lead.

The lead female characters are similar in that they are both socially awkward and insecure but by befriending the male lead, they find inner strength and both the male and female leads learn things about themselves about become better people.

The bare bones story is quite similar, shy girl meets not shy guy who helps her come out of her shell and they end up improving each others lives in the long run.

Without giving anything away, there's at least one scene that is near identical to HanaDan as well as certain scenarios/situations that feel similar.

Same plot essentially but different conflicts! The leads sleep together and then part ways but somehow run into each other and then are constantly put together to do things where they have to not only deal with one another but their own emotions as well.

The female and male lead characters are quite similar. She's kind of spastic/all over the place and super expressive/emotional, he's standoffish/ introverted and intimidating to others, she ignores all that and interacts with him anyways. It's a silly romantic-comedy at it's core.

(Re-post from the original version of this drama's page)

Female lead is not only the same actress, but the characters are suuuuuuper similar! Cheerful, optimistic, etc etc.

Supporting female is also similar: Rude and obnoxious model/actress who become likable.