This study was conducted to clarify the competency structure of kokoyakyu (Japanese high-school baseball) managers required by players. First, we interviewed 30 kokoyakyu OB players, and identified 127 competency items. To categorize these items, 1 professor and 3 graduate students in sports pedagogy discussed them until a consensus was reached. This yielded 62 competency items that were divided into 13 categories. Second, to appraise the reliability and validity of the resulting structure, we collected questionnaires from 800 kokoyakyu players. Corrected item-total correlation analysis, exploratory factor analysis, and confirmatory factor analysis revealed 4 factors comprising 22 competency items: (1) Reasonable coaching (8 items), (2) Mental and physical care consciousness (5 items), (3) Personalized coaching (5 items), and (4) Transcendental consciousness (4 items). The model data fit indices were c²/df = 2.264, GFI = .903, CFI = .940, RMSEA = .056. Construct validation was assessed by convergent validity (Cronbach's alpha, extracted mean variance, and construct reliability), discriminative validity, and player profile. According to the player's profile, “Reasonable coaching”, “Personalized coaching” and “Transcendental consciousness” were significantly higher in high-ranking schools than in low-ranking schools, and “Mental and physical care consciousness” was significantly higher in nonregular players than in regular players. Therefore, we judged that this structure is an appropriate indicator of the competency of kokoyakyu managers required by players.