TAKIZAWA, Yu. Investigating the cross-sectional and longitudinal relationship of X and LINE use with online relationship and life satisfaction: A 4-Year cohort study among Japanese adults. Cyberpsychology: Journal of Psychosocial Research on Cyberspace. 2025, vol. 19, no. 4, p. Article 2. DOI: 10.5817/CP2025-4-2