Origin: Jin became jealous of Michael's interactions with Sun.
Prize: Jin's watch
Fuel: Michael disapproved of the harsh tones Jin used when speaking to Sun. Then Michael found a watch on the beach and decided to wear it, not knowing that it actually belonged to Jin's Father-in-law, Mr. Paik. Jin thought that Michael had stolen it, and nearly drowned Michael in retribution. Because supposedly no one could translate, racial tension was the presumed motive, and the Losties handcuffed Jin to the wreckage ("House of the Rising Sun"). Because of their history of confrontation, Michael automatically blamed Jin for setting the first raft on fire ("...In Translation").
Resolved: Yes. Sun eventually admitted to speaking English, which broke down some of the communication barrier. Jin helped Michael build a second raft, and the two became close friends. Jin's opinion of Michael likely changed after learning his responsibility in Ana Lucia and Libby's death, but right before Michael's death on the Kahana, Jin risked his own life in helping him freeze the bomb, only leaving when Michael made him.
Fuel: Locke found Walt's dog, Vincent, with a whistle he had made when Michael couldn't; Yet he insisted that Michael take the credit for it ("Tabula Rasa"). Walt admired Locke for this and Locke returned the favor by teaching Walt how to throw knives ("Special"). Walt insisted on spending time with him, despite his father's jealousy of Locke.
Resolved: Yes. They worked together to rescue Walt from a polar bear, and afterward were amiable until Michael betrayed the survivors.
Since Then: The two only interacted occasionally during their first time together on the island. Michael agreed with Sayid's decision to stay on the beach, saying that doing so would more find rescue for him and Walt. The two shared an awkward moment when Michael explained Jin's attack on him; Michael angrily asked "Where are you from?", and Sayid's reply ("Tikrit") seemed to throw him off. Sayid constructed a radar from Michael's raft and helped launch it. Michael soon returned to the Island, and when Ana-Lucia shot Shannon, both men spent some time in her custody. After Michael's stay with the Others, Sayid correctly concluded that he had been "compromised". Michael refused to let him join him when he turned his friends over to the Others. Some time afterward, Sayid boarded the freighter and discovered Michael there using a flase name. He let him tell his story, but when he learned he worked for Ben, he revealed his identity to the rest of the ship.
Origin: Michael stumbled upon Sun when she was bathing.
Since Then: Michael started leaving Walt with Sun. When Jin attacked him, Sun admitted to Michael that she knew English, and the two grew closer. The two almost kissed in the jungle once, but Vincent interrupted them. Michael later tried defending her from Jin, but she slapped him, taking her husband's side. They parted awkwardly when Michael boarded the raft.
When Michael returned to camp after his time with the tail section, Sun was the first person he saw. He reunited with her again after his time with the Others, hugging her and Jin. After he left the Island, Hurley presumably told her abouthis betrayal. The two met again weeks later aboard the freighter, and Michael congratulated Sun on her pregnancy.
Origin: Michael and Susan were in a relationship when Susan gets pregnant with their son, Walt, but due to Susan's wishes they do not get married.
Since Then: After Walt was born, Susan was offered a job as an international lawyer but the job required her to move to Amsterdam. She tells Michael that she's taking the job and taking Walt with her. Michael strongly protests the idea, but relents. While in Amsterdam, Susan falls in love with her boss, Brian Porter. When she tells Michael this over the phone, Michael gets angry and hangs up the phone and is immediately struck by oncoming traffic while crossing the street. Susan visits him at the rehabilitation center, and tells Michael that she and Brian are getting married. She wants Michael to allow Brian to adopt Walt. Although Michael fights to retain his legal right as Walt's father, he ultimately allows Susan and Brian full custody of Walt. When Walt is around 10 years old, Susan contracts an illness and dies.
Origin: Tom's boat spotted Michael's raft. Michael explained his position, but rather than offering help, Tom said he was "going to have to take the boy."
Since Then: When Michael approached the Others, Tom saw him, fired a few shots at him and eventually overpowered him. Tom hooded Michael, and when he removed the hood, Michael spat in his face. The man spent the next several days with the Others, and Tom was on the dock when Michael piloted a boat off the island. Tom then left the island and kept tabs on Michael, eventually approaching him just as he was about to shoot himself. The two briefly fought and Tom left him his address. Michael soon discovered that he couldn't kill himself, and he visited Tom's hotel. he found Tom enjoying food and company, and he looked on in disgust. Tom presented him with a new identity - Kevin Johnson - and sent him on the freighter. Soon after he boarded the boat, Michael received a last call from Tom, reminding him that his friends' safety depended on his obedience.
Origin: Michael is Walt's father. Michael and Walt's mother separated, and they didn't meet until shortly before Oceanic Flight 815.
Since Then: The two bonded on the Island. They left the Island on a raft, and when the Others kidnapped Walt, Michael pursued them to get him back. He managed to leave the Island with Walt, but only by betraying his friends and killing two people. When he explained his actions to Walt off-Island, his son wouldn't forgive him. Walt moved in with Michael's mother, and Michael died before the two met again. Years later, Walt returned to the Island to help his father move on.