It has been more than 30 years since the identical twin sister of Japanese teacher Misa Morimoto vanished, believed to have been abducted by North Korea.

Hopes for her return have often surged and ebbed since, tracing the ups and downs of ties between Tokyo and Pyongyang.

Now Morimoto, 54, is cautiously optimistic that a planned summit between U.S. President Donald Trump and North Korean leader Kim Jong Un in Singapore on June 12 could bring news of the sister who resembled her so much that few could tell them apart.