It should be new balance shoes. This brand of sports shoes is very popular in Korea. Before this, the younger generation Jintan wore this brand of shoes. As for the squares, stickers should be attached to prevent the brand from leaking out, because the advertising placement in Korean TV dramas can't be as naked as that in domestic TV dramas, and even sponsors should use stickers to stick trademarks. In many Korean dramas, the Samsung logo of Samsung mobile phone is posted, and the logo of the car is also posted. Sponsors in Korean dramas will appear at the end of an episode.