Studio Tomboy, a fashion brand under Shinsegae International, has achieved remarkable sales success through its summer campaign featuring ATEEZ member Wooyoung. Following the launch of the Y2K-concept campaign 'Rewind. Replay. Now' last month, men's line new product sales increased by 73% over the same period. The campaign, which reinterprets 1990-2000s culture and fashion in a contemporary way, showcased vintage casual styles using check shirts, stripe t-shirts, denim, and cargo pants. The 'Hoodie Small Check Shirt' worn by Wooyoung sold out immediately after the campaign launch. The 'Pocket Embroidery Detail Check Shirt' exceeded 80% sales rate with the pink color entering additional production, while the 'Western Core Check Shirt' also sold out with further shortages expected. The collaboration with the globally recognized K-pop artist successfully converted brand awareness into actual purchases, demonstrating the effectiveness of fandom marketing.