Cry Me a Sad River (2019)

They are under the same genres: romance, school, youth, friendship, slice of life.
I feel like My youth has a similar setting to River flows to you. This focuses on friendship. The boy is always there for the girl no matter what. There are rivals too ;)
RFTY shows a boy and a girl who grew up together and one eventually falls in love with the other, which is quite similar to my youth .

Differences

River flows to you has more family involvement

The girl is very poor in RFTY

Few friends

Main lead and Female lead are neighbours and childhood friends, have great bond with eachother

Both can't stay away from eachother and Male lead does a lot for Female lead without showing that he love her inspite of being so popular and rich at school

Both involves the tragedies and different people the Main lead meets in life and their family backgrounds

Female lead have no idea that her best friend like her, she takes him as her best friend initially

Female lead is strong and have her own view about her life to change her lifestyle. Both female leads start working part time.

In both series you will realize how beautiful it is to have somebody by yourside and both of them defines value of love and friendships.

Like A river runs through it, River flows to you is also shot in neighbourhood. You will get to see a lot of college scenes and neighbourhood scenes.

Be prepared for a lot of melodrama, both series have ups and downs. So keep the tissue box closer while bingewatching them.

Same female lead, and same author.
And the whole air and setting.... It's pretty similar. Other than that, the major issues regarding the storyline are quite different.
Both follow the lives of multiple characters and couples, and also depict the workplace struggle.