Based on the "Differential Susceptibility Theory," we examined whether the relationship between pubertal maturation and depressive symptoms can be moderated by individual differences in environmental sensitivity. The current article used the three-wave data collected from Japanese adolescents aged from 12 to 15 years (girls = 111, boys = 98). Consequently, a significant Sensitivity × Pubertal Development interaction was observed in 12- to 13-year-old boys, but not girls. Sensitive boys who experienced accelerated physical maturation reported decreased depressive symptoms, while those who experienced less maturation had increased depressive symptoms. The shape of the interaction supported both the "Differential Susceptibility Theory" and the "Diathesis-StressModel." Our findings suggest that sensitivity during early puberty among boys could be reconsidered as "susceptibility" rather than "vulnerability."