Interchange stations between the Island , Tsuen Wan , Kwun Tong and Tseung Kwan O lines are arranged in pairs ; such an arrangement allows cross-platform interchange wherein a passenger leaves a train on one side of the platform and boards trains on the other side of the platform for another line . The interchange between the Tsuen Wan Line and the Kwun Tong Line , the Island Line and the Tseung Kwan O Line , as well as that between the Kwun Tong Line and the Tseung Kwan O Line , are two stations long , allowing cross-platform interchange wherein a passenger leaves a train on one side of the platform and boards trains on the other side of the platform for another line .