Luna fondly remembered her training days during her appearance on MBC's 'Radio Star' on May 27.

She revealed that her role model was BoA, saying, "I practiced to the point I bled from both nostrils to be like BoA."

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She went into further detail, elaborating, "When I was a 14 or 15-year-old trainee, I had to leave at 9 o'clock.  However, I'd pretend to leave and actually go up to the third floor practice room to practice until 4 or 5 in the morning.

"I was tired, so I didn't even know if I was sleeping.  However, my dad told me I was sleeping atop the shoe rack.  Also, he said he was shocked because I was bleeding from both nostrils, but I was happy about that.  It made me think I was also working hard."