Upon the declaration of martial rule in the Philippines, X, together with his wife and children, disappeared from his residence along Ermita, Manila. Years passed without Y hearing from X and his family. Y continued taking care of X's house, even causing minor repairs to be done at his house to preserve it. In 1976, when business began to perk up in the area, Z, approached Y and proposed that they build stores at the ground floor of the house and convert its second floor into a pension house. Y agreed to Z's proposal and together they spent for the construction of stores at the ground floor and the conversion of the second floor into a pension house. While construction was going on, fire occurred at a nearby house. The houses at the entire block, including X's, were burned. After the EDSA revolution in February 1986, X and his family returned from the United States where they took refuge in 1972. What is the juridical relation between X and Y? Explain