public class Person implements Serializable {

    @Id
    private final String id = UUID.randomUUID().toString();

    @Column
    private String name;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "person", orphanRemoval = false, fetch = FetchType.LAZY)
    @JsonManagedReference("bankCards")
    @Valid
    @Size(min = 1)
    private List<BankCard> bankCards = new ArrayList<>();
}

@Data
@Entity
@Table(name = "lazy_test_bank_card")
public class BankCard implements Serializable {

    @Id
    private final String id = UUID.randomUUID().toString();

    @Column
    private String bankName;

    @ManyToOne(optional = false,fetch = FetchType.LAZY)
    @JoinColumn(name = "person_id")
    @JsonBackReference("bankCards")
    private Person person;
}

import com.omg.lazyLoadingTest.model.BankCard;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

@Repository
@Transactional
public interface BankCardRepository extends JpaRepository<BankCard, String>,
                                 JpaSpecificationExecutor<BankCard> {

}

import com.omg.lazyLoadingTest.model.BankCard;
import com.omg.lazyLoadingTest.model.Person;
import com.omg.lazyLoadingTest.repository.BankCardRepository;
import com.omg.lazyLoadingTest.repository.PersonRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@RequestMapping("/test")
public class TestController {
    @Autowired
    private PersonRepository personRepository;

    @Autowired
    private BankCardRepository bankCardRepository;

    @GetMapping(path = "/person1/{id}")
    public Person person1(@PathVariable String id) {
        Person person = personRepository.findOne(id);
        //At this case ,@OneToMany lazy loading worked, it will not load the 'bankCards'
        return person;
    }

   
    @GetMapping(path = "/bankCard/{id}")
    public BankCard bankCard(@PathVariable String id) {
        BankCard bankCard = bankCardRepository.findOne(id);
		//However at this case, @ManyToOne lazy loading not worked, it will load the 'person' although I configured FetchType.LAZY
        return bankCard;
    }
}

Hibernate: select bankcard0_.id as id1_0_0_, bankcard0_.bank_name as bank_nam2_0_0_, bankcard0_.person_id as person_i3_0_0_ from lazy_test_bank_card bankcard0_ where bankcard0_.id=?
Hibernate: select person0_.id as id1_2_0_, person0_.name as name2_2_0_ from lazy_test_person person0_ where person0_.id=?