The couples with most popularity of OP in Japan

The couples most beloved and popular of One Piece in Japan:

Since 1: Luffy x Nami (LuNa) - (The LuNa in other countries, how in Europe, America and Asia it's popularity is much most big that in the own Japan, being also the couple most popular of One Piece in the world).

Since 2: Franky x Robin.

Since 3: Zoro x Tashigi.

Since 4: Usopp x Kaya

Since 5: Sanji x Viola 

Since 6: Ace x Moda 

Since 7: Law x Monet

Since 8: Mihawk x Perona 

Since 9: Shanks x Makino

Other couple who are having popularity is the Sabo x Koala.