Dramas with cute ML

You didn't mention the Country so i'm just gonna mention a mix.

Meow, the Secret Boy 

The Romance of Tiger and Rose - ML isn't really naive but he is adorable ans the FL helps him sometimes.

Backstreet Rookie - Airing drama.

I Cannot Hug You 

The Tale of Nokdu  

Oh My General 

Introverted Boss 

Kill Me, Heal Me - ML is cute and some of his personalities are naive. FL helps him.

To Get Her 

Just Between Lovers - They help each other and become stronger (emotionally).

Arsenal Military Academy  - Highly recommend! (Is set in republican era though)

The Princess Wei Young  - Helps ML a lot. ML is adorable but strong and the FL is strong (Mentally)

I Hear Your Voice - cute and teenage like Lee Jong Suk

Mysthic pop up bar - the cutest one out there ^^

When the weather is fine - I found him to be cute and shy even in their relationship/interactions

Angel's last mission: love - he is the cute type and being an angel makes him quite naive 

Iine! Hikaru Genji-kun

ONE SPRING NIGHT 

THIRTY BUT SEVENTEEN 

JUGGGLERS

ENCOUNTER 

IM NOT A  ROBOT