Monkey D. Luffy is the love interest of Boa Hancock from One Piece.
Luffy is the teenage captain of the Straw Hat pirates. He has the power to stretch his entire body after eating the cursed gum-gum fruit, though he can't swim as a result. His lifelong dream is to become King of the Pirates.
Hancock originally had an antagonistic relationship with him. She has a hard time looking Luffy in the eye and tends to blush in his presence. She daydreams about Luffy. Her love for Luffy caused her to turn against the World Government on a number of occasions. She has a demure behavior when she is around Luffy showing that she loves him. She also yells at Aokiji for killing Luffy with an Ice Saber and has a really bad temper. Her time with Luffy has changed her personality considerably since from before. During the Battle of Marineford, she states that all men, both Marine and pirate alike are her enemies. When Luffy arrives, she focuses her attention on him. She barely expressed her desire to be the one to have taken all the suffering in Luffy's place. She cares for Luffy that she barely ate any food on her return to Amazon Lily until she makes sure Luffy is alright.
Since Luffy has no feelings towards her, Hancock is always loyal to him. Luffy also protected Hancock by declaring he would not tell Magellan even if it killed him. He showed his gratitude by hugging her and remarking afterward that she had saved him twice, both in helping him break into Impel Down and giving him the key to Ace's seastone handcuffs.