Singer and actor Rain joined the ice bucket challenge for CEO Hong Seung Sung.

On August 23, Rain posted on Cube Entertainment's YouTube channel a video of his ice bucket challenge.

In the video, Rain said, "The meaning of joining the ice bucket challenge is very deep for me. My teacher and father who made me as singer 'Rain' has been fighting the Lou Gehrig's Disease for 3 years now."

He continued, "I always thought about how to show my gratitude to him. A hospital in Korea is currently working on a new medicine for the disease. I want to donate to a good cause," donating about $100,000 to that research.

Hong Seung Sung is the CEO of Cube Entertainment and was diagnosed with the Lou Gehrig's Disease. He has been taking care of the company's system despite his health.