Put Your Head on My Shoulder (2019)

They are actually sister dramas! All based on the same author's novels too. Although "Put Your Head on My Shoulder" is still ongoing, I liked every episode of it so far (even more than "A Love So Beautiful". They are both so heartwarming (especially PYHoMS) with great character developments and include school life (with PYHoMS starting from college and ALSB from high school). If you liked one drama, you'll like the other. Both are very light and you will find yourself with a big smile on your face after every episode.

Same actors; similar level of sweetness
Watch if you're into cute romantic fluff with supportive side characters and relatively little scheming second leads!

Put Your Head on my Shoulder is the youthful, perky, cuter version of Because This is My First Life. Both dramas have similar elements (but different circumstances, mainly because BTIMFL couple are adults).

1. Cohabitation
2. A contract
3. Intellectual male lead who never treated the female lead badly
4. Cute female lead
5. Drinking beer while watching TV
6. Leads were away from each other for a while
7. Third party FL who is not annoying
8. A cat

Fluffy, pure romances with little extraneous drama. The leads have great chemistry in both. When you're looking for a sweet romance, these fit the bill.

I haven't finished PYHoMS yet because it is still ongoing, but from the 8 episodes I have watched already, they are both very light hearted, fluffy and heartwarming! The main characters have unwavering love for each other. Both includes college life and has very smart male leads. Although the girl is not as smart as the male lead, but still very smart because the male leads are geniuses that can't be compared to... The personalities for the main leads are so sweet and cute too.

The male lead reminds me of Gu We Yi and the way that their relationship starts it’s almost the same

Both are college dramas and very light-hearted. The male leads are both standoffish and smart but they are the ones that fall in love first. Both dramas' couple chemistry is cute and off the charts. There isn't much family drama either. Both similar to drama love 020

It is a college campus story between the leads.
There might be a love square between the 4 characters of the drama.
The chemistry is undeniably strong.
The female lead is cute, quirky and cheerful
The male lead is subtle, shy and kinda quiet.

Not only do they have basically the same vibe, they both share alot of similarities:
+ Both MLs are geniuses (Maths in Perfect and Casual, Science in Put Your Head On My Shoulder)
+ Both MLS are sort of cold to start with - but are extremely caring and protective, jealous of a SML at the beginning and do their best to make the FL stay
+ Contracts: In Perfect and Casual it's a marriage contract - in Put Your Head On My Shoulder there is a contract for the FL to keep living there by her mom
+ A lot of fluff
+ Both have hardworking FLs where the ML sometimes helps out in cute and supportive ways with their knowledge
Funny note, both FLs like snail noodles which the MLs hate lol

Both are sweet non toxic dramas with excellent chemistry. Male leads has many similarities too
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Both are about college students falling in love. Both lead males are incredible good looking and female leads are both cute.

At first genius mathematician boy and artistic girl don't get along at first but as time goes by they fall in love. The girl tries to follow him to the same school with the same major but the boy doesn't want her to do that. Of course there are the nagging love triangles to make the story interesting.

Both are College Dramas that are light, sweet and will have you grinning in most parts of the show. The romance isn’t instant and the main leads started off just friends. Both dramas can be recommended for newbie kdrama and cdrama fans.

I think they have a similar vibe. DISCLAIMER I am only up to ep 31 on First love.
PYHOMS is more focused on the romance of the main couple than in First love and has lots more Awww moments. The romance in First love is slower moving and a little more "innocent".
Both have;
Long distant relationship/breakup (SPOILER;which I did not like in First love)
No real bad guy characters.
Characters stay true to eachother.
Smart ML willing to do almost anything for their girl.

More time spent on the main leads relationships with friends and family in First love.
PYHOMS starts at university and continues on to worklife for some characters while First love starts in high school and continues into university life.
I like the stories of the secondary characters in first love better than in PYHOMS.

Co-Habitation
Genious Cold-Male Lead who treats the FL warmly
Plus there's one scene that is a copy of each other. (Not gonna spoil which one)