Singer Park Nam-jung and his daughter Si-eun performed BTS Jungkook's "3D" on KBS2's "Immortal Songs" episode 735. This broadcast was themed "2025 Year-End Special - Family Vocal Battle," featuring not only Park Nam-jung and Si-eun but also Yoon Min-soo and Kim Kyung-ja mother and son, Kan Mi-yeon and Hwang Ba-ul couple, Jannabi and Choi Jung-joon brothers, and Woody and Kim Sang-soo brothers.

Park Nam-jung and Si-eun prepared a collaborative stage combining BTS Jungkook's "3D" and Park Nam-jung's "Days Touched by Rain," released 33 years ago. Their song choice and performance, bridging two generations, drew great anticipation even before the stage. Park Nam-jung expressed his feelings about performing with his daughter, saying, "I learned a lot while practicing," and added, "Having worked alone, I practiced a lot recently as I encountered music and dance that fit current trends."

Si-eun said, "Since my debut, I have always imagined performing on stage with my dad," and continued, "I was surprised that the opportunity came sooner than expected, and I approached it with gratitude as it was a meaningful stage." However, the rehearsal process was not smooth. Park Nam-jung revealed an anecdote about being scolded by his daughter, saying, "She said I was too free-spirited." During the rehearsal scenes, Park Nam-jung was shown losing track of his movements and confusing the order of steps, receiving corrections from Si-eun.

Si-eun showed respect, saying, "Still, my dad didn't give up. When practicing, he was a perfectionist who saw it through to the end," and added, "That's when I thought, 'There is a reason for his reputation.'" Park Nam-jung also candidly spoke about his daughter's talent. He said, "I thought all kids were like that when they were young, but Si-eun is definitely exceptional," and added, "Now, there is almost nothing left for me to teach her; I am learning from her from A to Z. As Si-eun coaches me, I feel myself improving."

On stage, Park Nam-jung perfectly executed Jungkook's "3D," proving his enduring status as a "dance legend." However, they ultimately lost to Woody and Kim Sang-soo brothers, failing to secure a win. This stage showcased the strong bond between father and daughter, and their collaboration moved many viewers.

This broadcast mainly featured family-based performances, with various artists sharing the stage to showcase their unique charms. Park Nam-jung and Si-eun's performance was especially regarded as a meaningful occasion symbolizing musical exchange between generations. Their collaboration raised expectations for future musical activities.

Through a stage combining past hits and the latest trends, Park Nam-jung broke down generational barriers and explored new musical possibilities with Si-eun. Viewers were able to feel once again the power of family love and music through their performance.

This broadcast served as an opportunity to reemphasize the importance of family and the power of music, and Park Nam-jung and Si-eun's activities are expected to continue attracting attention. Their stage remained an important moment that went beyond a simple performance, showing the bond between family and musical passion.