Introduction:
Motivation is a critical factor in second language acquisition, and it is a concern that many Japanese university learners struggle to sustain it. The L2 Motivational Self System (Dörnyei, 2005, 2009) posits that motivation is driven by the discrepancy between learners' Ideal L2 Self and their Current L2 Self. However, the psychological processes that shape this self-discrepancy, particularly the role of self-appraisal, remain underexplored. Self-appraisal, which pertains to a learner's confidence in their performance, is believed to influence how they construct their self-images, yet empirical validation is scarce. This study aims to clarify the mechanism by which self-appraisal affects self-images, self-discrepancy, and motivation.
Purpose: To investigate how self-appraisal predicts (1) self-images (Ideal and Current L2 Selves), (2) self-discrepancy, and (3) the motivational effectiveness of self-discrepancy.


Method:
A total of 253 Japanese university EFL learners completed an English proficiency test and a questionnaire measuring self-appraisal (confidence towards the test), self-images (Ideal and Current L2 Selves), self-discrepancy, and Intended Learning Effort. Multigroup structural equation modeling (SEM) and polynomial regression were employed to explore the relationships across different levels of self-appraisal.


Results:
Self-appraisal significantly predicted both Ideal and Current L2 Selves, with higher confidence associated with more positive self-images. It also significantly predicted self-discrepancy: learners with higher confidence reported smaller self-discrepancies. Crucially, the explanatory power of self-discrepancy on motivation was significant only among learners with moderate confidence who demonstrated moderate level of self-discrepancy. Moreover, a curvilinear relationship emerged, suggesting that motivation is maximized when the discrepancy between Ideal and Current L2 Selves is neither too large nor too small.


Conclusion:
This study demonstrates that learners' confidence meaningfully shapes the construction and motivational function of L2 self-images. The findings offer practical implications for applied psychology and language education, particularly in designing interventions that foster accurate and motivating self-perceptions.