Whereas much research on interest development focuses on single, predefined, and generic objects of interest (e.g., science) in specific contexts (e.g., science classroom), this study proposes a person-objects-contexts (i.e., P-O-Cs) perspective that accounts for idiosyncrasy and multiplicity of interests and contexts and consequent intrapersonal dynamics. It reports a multiple case study in which four students were followed for over 2 years in transition from secondary to higher education. Data collection included seven waves of experience sampling of daily life interest experiences with the help of a newly developed smartphone application (inTin) and four biographical interviews per student. Analysis concentrates on the intrapersonal dynamics in interest development when pursuing multiple interests in multiple contexts, with study choice as a specific example. Results reveal how students' multiple and diverging interests differ in acrosscontext continuity, some being shared across school, family, and peer contexts. Academic and nonacademic interests are found not to be fixed and independent in their development, rather showing patterns of differentiation and integration in the interests over time. Moreover, students display parallel, sequential, and combined pursuance of interests in study and leisure time. We conclude how interest development is nonlinear and more fluid than typically theorized.