watch this if you really like the small-town/country vibes of this drama. I
It's very chill and relaxing and it does have some other subplots, but it is very slice-of-life focused.
(subplots include some romance and a mystery)

1) main love interest isn't defined. (kinda plot twisty)
2) a manipulative little she-devil side character that wants to steal one of the love interests

(that's the only thing they have in common. everything else is different lol)

1) the main love interest isn't clear in either of these (the whole time, she could go with either one)
2) the one that plays Sea in Peach Girl is the main lead in Daytime Shooting Star

This is for the people that like to cry to movies

Summoned by an unexpected phone call, an elderly woman visits a cottage she used to live in as a child. She begins to recall her memories of a boy she knew 60 years ago.
The young Suni and her family move to a small rural village in Korea. There, they encounter a strange ‘wolf boy’ hiding under a bush and take him in out of pity. Bothered by his wild eyes and feral behavior, Suni teaches the boy to wait patiently before a meal, put on clothes, and read and write the alphabet so that he can one day live like other human beings. Slowly, the boy begins to develop feelings for Suni, the first person to ever show him affection. Then one day an unexpected threat exposes the boy’s deadly bestial instincts, and in an instant, he becomes the subject of the villagers’ fears. Desperate to save the life of the boy who risked his own to be by her side, Suni leaves him with a promise: ‘Wait for me. I’ll come back for you.’

It has a surprise plot twist in the end in regards of the guy that gets the girl. If you want to be fooled into thinking you are getting second lead syndrome then this is the movie for you my friend. In fact, I found this movie because of a recommendation that i saw on the recommendations page of "4-gatsu no Kimi, Spica". And they are indeed similar script-wise. I hope this is useful to someone.

If you liked the actor that plays Cai Yasi, here is another one of his projects. (In this drama, he is also a second lead though so sorry to disappoint.)

And for those others who don't like Cai Yasi, this drama is just something you would enjoy, in my opinion, if you liked "The Love Equations".

Hella cute as well as this drama.
The main lead also go through a love patch (for those who like the mild heartbreak in the middle of the serie)