From the synopsis alone one can see that there will be some similarities between the two drama like it is a North-South Korean romance,the fl is a soldier and the ml is famous
Will update this when it airs though

Both drama are about a contract relationship that blooms into love and understanding. Opposites attract and life-doesnt-go-the-way-you-want-it are themes that appear in both drama.
Though BTIMFL is more of a slow paced and mature slice of life and Begin Again is more active and playful rom com, both drama couples had an amazing flow. Both drama could easily become off putting due to the plot itself but the actors in both cases did a really good job delivering their roles. You might not understand or agree with the mcs' choices so keep that in mind.

Ghost love stories~ what would happen if you fell in love with a ghost??? Both drama deal with this question. Though one is contemporary and the other is historical one can feel the dedication of the mls to not let go of their love despite the obvious adversities. They also have their fair share of comedy.

Crime meets supernatural. Many ghosts cases that get solved throughout the drama while our main leads deal with their own mysteries and troubles and a dash of complicated past.

The similarities... Damn it i wont spoil you but you will definitely feel more about the second main leads. They are honestly the show stealers. Though the main couples are ok the sls is real. Especially all that doomed love theme about them...

Ghosts, intrigues, a bit of thriller and trying to unveil a past incident in order for our mcs to finally move on. Though all this if you focus in the ghost part of Oh My Ghostess(leave out the romance part).

I might spoil you so lets just say that both drama have similar elements and moods. Both drama are about love and acceptance. Both drama show the struggle that comes along with being yourself and love the person you love in a world that doesn't seem to accept you. Though Ototo no Otto focuses more on family and Make your Days Count is a romance drama, they both show love in all its glory and pain.

*may contain spoilers*
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In both drama our fl falls in love first but does so without knowing a very important detail that the ml knows and hides from her until things escalate. Although the secrets arent similar they both have to do with a third person and their involvement with both of our mcs. Family is also an important presence in both drama as is the fact that our ml has an issue that has to do with his brain.

Showbiz, secrets and our ml didn't really like our fl in the beginning but they got together after dealing with lots of rumours and troubles. Also the fl has to deal with a bad reputation at first and the ml has a medical condition.

Both drama are office romances that revolve around an older woman and a younger man. There is some business related issues along with some questions that one asks as they grow up and start working. Both drama dont try to portray perfect characters but they show them as regular people, sometimes as a coward or a bit problematic in some incidents.

Wish granting shop open for service. Are you ready to pay the price of getting your wish granted? Because there is always a price. To sum it up both drama focus on human mind, wishes, greed and deal the question of what every person thinks as most valuable in their life. Also the boss is a marvelous witch.

Both drama have:
•gaming/e-sports,
•genius ML
•Issues created by rumours and fame
•awkward and guarded interactions that slowly evolve through each episode to cute couple dynamics aka kind of a slow burn romance