Cong Minh

I think Shintaro is a yandere type of character, which I personally find interesting

I love how Seo Joon remains his usual self (eccentric and annoying lol) despite how cold-hearted Ji Woo treats him, instead of breaking into tears every other scene.

The second couple is Park and Lee. I don't know why some of the comments below say it's Park and Tim. It's not hard to remember coz Park and Lee are two common Korean family names lol

I think Namning's mother is the mistress. That's why she has to respect the other wife in front of her. And I'm pretty sure I heard Namning's father refers to the other wife as her Big Mother. In short, both her and her mother are homewreckers