Hatsu Bakery Seongsu is a bakery in Seongsu, Seoul that sells sand bagels and baguettes. Its signature items are the strawberry yochike sand bagel, mentaiko baguette, and basil baguette. On weekends, a line forms before its 10:30 a.m. opening, and waits for takeout and in-store seating run about an hour. The bread is good, but the prices are high.