What are some disturbing Asian films?

I haven't seen all of them but these sound "disturbing" (in different ways), and they're not on your watched list.

• Old Boy
• Over Your Dead Body
• The older adaptation of Fires on the Plain
• Caterpillar

VIP is the most gruesome and disturbing movie I watched till yet...

I can recommend: 

• Pieta (directed by Kim Ki Duk)
• Mother (directed by Bong Joon Ho)

For something really crazy and twisted: Visitor Q (Takashi Miike ) 

- Love exposure 

- Rage (Anger)

And more or less (depends on your sensivity : heavy themes, psychological, violence) :

- Pluto

- Night flight

- The king

- Bleak Night

- One Way Trip

- To Each His Own

- Pink and Gray

- Believer

• +1 to Visitor Q and The Isle
• Air Doll
• Beautiful
• Caterpillar
• Helter Skelter
• Pulse
• Snakes and Earrings
• The Vengeance Trilogy
• Strange Circus
•  Tag (really anything by Sion Sono)
• Any films based on Junji Ito’s works
  
  

1.  Happy End
2. A Man and a Woman

reasons: It involves poor child who are innocent, for whatever reason the mother had affair with other man. I don't really understand "pursue your own happiness, even if it means to abandon everything/one you used to love (husband, children, family)". Anyone should know marriage is not a 24/7 love story, quarrel fight jealousy should be expected in marriage. 

Conclusion: don't get married and even think to have  a child if you don't have the courage to walk through a storm. Because you will just end up hurting a lot more people.