The two had worked together in '7th Grade Civil Servant', and Ahn Nae Sang spoke up about his experience with the idol on 'Baek Ji Yeon's People Inside'. First, he watched a video message Chansung sent him where the idol said, "Before we started filming, he gave me a special lesson. He told me, 'I think the character Gong Do Ha should be like this', and gave me personal lessons. He was so kind to me. I was so thankful, and he's a sunbaenim I respect."

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After the video, Ahn Nae Sang confessed, "At first, I found approaching Chansung difficult because he was an idol. But he's a really nice guy. I thought he'd be cocky being an idol group member and a hallyu star, but he was actually very polite and sincere. He is the type of person who has the ability to make you feel good. After filming, we kept talking and even texted each other. Even though it was his first time acting, he acted very well. I praised him a lot because it was my way of showing him gratitude for the times he lifted my spirits."

With his polite and sincere attitude with good looks to boot, it seems like Chansung is rapidly rising up on fangirls' lists of perfect boyfriend material!