Introduction: Nurturing “basic societal competencies” is important in the training education of speech-language-hearing therapists (SLHTs) to enable them to respond to fluctuating medical treatment scenarios. However, in the current training education for SLHTs, some students need assistance in terms of basic societal competencies, such as initiative, planning, and communication. In this study, the focus was on coaching theory, a method of interpersonal support through dialog, as a strategy for addressing the issues. The objective was to clarify whether coaching theory-based classes for SLHT students improve their basic societal competencies. Methods: The participants were first- and third-year undergraduate SLHT students in Japan. The coaching and control groups comprised students enrolled in 2021 and 2020, respectively. The observation period for this prospective cohort study was from April to September 2020 and from April to September 2021. The coaching and control groups received 90-min coaching and remedial education classes, respectively, 11 times in 3 months. To establish students’ knowledge and skills, follow-up sessions were conducted four times a month, and assignments were given during the subsequent summer vacation. The effects of the classes were based on Kirkpatrick’s four-level evaluation model, with Levels 1, 2, 3, and 4 evaluating satisfaction with the class, learning proficiency, behavior modification, and result attainment, respectively. Results: The coaching and control groups comprised 40 and 48 participants, respectively. In the evaluation of behavior modification (level 3) using the “PROG (progress report on generic skills) competency test (RIASEC Inc., Tokyo),” the interactions between time and group and the main effects of time were significant for the basic societal competencies of “relating with others” and “self-confidence.” Multiple comparisons showed that the post-class scores were significantly higher than the pre-class scores in the coaching group (change of 0.9 for relating with others and 0.7 for self-confidence) and that the scores in the coaching group were significantly higher than those in the control group at the post-class. The interaction between time and group was significant for those “planning solutions,” and the post-class score was significantly higher than the pre-class score in the coaching group (change of 0.8). Conclusion and Implication: The coaching classes improved the students’ basic societal competencies of relating with others, self-confidence, and planning solutions. This suggests that coaching classes are useful in the training education for SLHTs. Ultimately, nurturing students’ basic societal competencies will develop human resources who could achieve quality clinical performance.